24 CFR Part 3280 — Manufactured Home Construction and Safety Standards

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PART 3280—MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Authority: 15 U.S.C. 2697, 42 U.S.C. 3535(d), 5403, and 5424. Source: 40 FR 58752, Dec. 18, 1975, unless otherwise noted. Redesignated at 44 FR 20679, Apr. 6, 1979. Subpart A—General § 3280.1 Scope. This standard covers all equipment and installations in the design, construction, transportation, fire safety, plumbing, heat-producing and electrical systems of manufactured homes which are designed to be used as dwelling units. This standard seeks to the maximum extent possible to establish performance requirements. In certain instances, however, the use of specific requirements is necessary. [58 FR 55002, Oct. 25, 1993] § 3280.2 Definitions. Definitions in this subpart are those common to all subparts of the standard and are in addition to the definitions provided in individual parts. The definitions are as follows: Approved, Attached accessory building or structure Bay window Certification label Dwelling Dwelling unit Equipment Federal manufactured home construction and safety standard Installations Labeled Length of a manufactured home Listed or certified Manufacturer Manufactured home Manufactured home construction Manufactured home safety Multipurpose fire sprinkler system Registered Engineer or Architect Secretary Stand-alone fire sprinkler system State Water resistive barrier Width of a manufactured home [40 FR 58752, Dec. 18, 1975, as amended at 42 FR 960, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 47 FR 28092, June 29, 1982; 58 FR 55002, Oct. 25, 1993; 61 FR 5216, Feb. 9, 1996; 72 FR 27228, May 14, 2007; 86 FR 2516, Jan. 12, 2021; 89 FR 75737, Sept. 16, 2024] § 3280.3 Manufactured home procedural and enforcement regulations, and consumer manual requirements. (a) A manufacturer must comply with the requirements of this part, part 3282 of this chapter, and 42 U.S.C. 5416. (b) Consumer manuals must be in accordance with § 3282.207 of this chapter. [86 FR 2516, Jan. 12, 2021] § 3280.4 Incorporation by reference. (a)(1) Certain material is incorporated by reference in this part with the approval of the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that specified in this section, the U.S. Department of Housing and Urban Development (Department) must publish a document in the Federal Register [email protected]; www.archives.gov/federal-register/cfr/ibr-locations [email protected]. (2) The IBR material may be obtained from the sources in this paragraph (a)(2) or from one or more private resellers listed in this paragraph (a)(2). For material that is no longer commercially available, contact the Office of Manufactured Housing Programs (see paragraph (a)(1) of this section). (i) Accuris Standards Store, phone: (800) 332-6077; website: https://store.accuristech.com. (ii) American National Standards Institute (see paragraph (h) of this section). (iii) EverySpec LLC, 710 Lake Louise Ct., Gibsonia, PA 10544; website: http://everyspec.com. (iv) GlobalSpec, 257 Fuller Road, Suite NFE 1100, Albany, NY 12203-3621; phone: (800) 261-2052; website: https://standards.globalspec.com. (v) Nimonik Document Center, 401 Roland Way, Suite 224, Oakland, CA, 94624; phone (650)591-7600; email: [email protected]; www.document-center.com. (b) Air Conditioning, Heating & Refrigeration Institute (AHRI), 2311 Wilson Blvd., Suite 400, Arlington, VA 22201; telephone: 703-524-8800; fax: 703-528-3816; website: www.ahrinet.org. (1) ANSI/AHRI Standard 210/240-2008 with Addenda 1 and 2, 2008 Standard for Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment, ANSI-approved December 2012; IBR approved for §§ 3280.511(b); 3280.703(d); 3280.714(a). (2) [Reserved] (c) Aluminum Association (AA), 1525 Wilson Blvd., Suite 600, Arlington, VA 22209; telephone: 703-358-2960; fax: 703-358-3921; website: www.aluminum.org. (1) Aluminum Design Manual, Specifications and Guidelines for Aluminum Structures, Part 1-A, Sixth Edition, October 1994; IBR approved for § 3280.304(b). (2) Aluminum Design Manual, Specifications and Guidelines for Aluminum Structures, Part 1-B, First Edition, October 1994; IBR approved for § 3280.304(b). (d) American Forest and Paper Association (AFPA), 1101 K Street NW, Suite 700, Washington, DC 20005; telephone: 202-463-2700; website: www.afandpa.org. (1) AFPA, Wood Structural Design Data, 1986 Edition with 1992 Revisions; IBR approved for § 3280.304(b). (2) [Reserved] (e) American Gas Association (AGA), 400 North Capitol Street NW, Washington, DC 20001: telephone: 202-824-7000; website: www.aga.org. (1) AGA No. 3-87, Requirements for Gas Connectors for Connection of Fixed Appliances for Outdoor Installation, Park Trailers, and Manufactured (Mobile) Homes to the Gas Supply; IBR approved for § 3280.703(d). (2) [Reserved] (f) American Institute of Steel Construction (AISC), 130 East Randolph Street, Suite 2000, Chicago, IL 60601-6219; telephone: 312-670-2400; fax: 312-626-2402; website: www.aisc.org. (1) ANSI/AISC 360-10, Specification for Structural Steel Buildings, Second Printing: February 2012 (AISC 360-10); IBR approved for §§ 3280.304(b); 3280.305(j). (2) [Reserved] (g) American Iron and Steel Institute (AISI), 25 Massachusetts Avenue NW, Suite 800, Washington, DC 20001; telephone: 202-452-7100; website: www.steel.org. (1) AISI S100-12, North American Specification for the Design of Cold-Formed Steel Structural Members, 2012 Edition, 2nd Printing—June 2014, including AISI S100-12-E3 errata dated December 10, 2014; IBR approved for §§ 3280.304(b); 3280.305(j). (2) [Reserved] (h) American National Standards Institute (ANSI), 25 West 43rd Street, 4th Floor, New York, NY 10018; telephone: 212-642-4900; fax: 212-398-0023; website: www.ansi.org. (1) ANSI A112.14.1-1975, Backflow Valves; IBR approved for § 3280.604(c). (2) ANSI A112.19.5-1979, Trim for Water Closet, Bowls, Tanks, and Urinals; IBR approved for § 3280.604(c). (3) ANSI/AITC A190.1-1992, For wood products—Structural Glued Laminated Timber; IBR approved for § 3280.304(b). (4) ANSI A208.2-2002, Medium Density Fiberboard (MDF) For Interior Applications, approved May 13, 2002; IBR approved for § 3280.304(b). (5) ANSI B16.18-1984, Cast Copper Alloy Solder-Joint Pressure Fittings; IBR approved for § 3280.604(c). (6) ANSI C72.1-1972, section 4.3.1, Household Automatic Electric Storage Type Water Heaters; IBR approved for § 3280.707(d). (7) ANSI Z21.22-1999, Relief Valves for Hot Water Supply Systems; IBR approved for §§ 3280.604(c); 3280.703(d). (8) ANSI Z34.1-1993, Third-Party Certification Programs for Products, Processes, and Services; IBR approved for §§ 3280.403(e); 3280.405(e). (9) ANSI Z97.1-2009 e (10) ANSI Z124.1-1987, Plastic Bathtub Units with Addendum Z124.1a-1990 and Z124.1b-1991; IBR approved for § 3280.604(c). (11) ANSI Z124.2-1987, Plastic Shower Receptors and Shower Stalls with Addendum Z124.2a-1990; IBR approved for § 3280.604(c). (12) ANSI Z124.3-1986, Plastic Lavatories with Addendum Z124.3a-1990; IBR approved for § 3280.604(c). (13) ANSI Z124.4-1986, Plastic Water Closets, Bowls, and Tanks with Addenda Z124.4a-1990; IBR approved for § 3280.604(c). (14) ANSI Z124.5-1997, Plastic Toilet (Water Closets) Seats; IBR approved for § 3280.604(c). (15) ANSI Z124.7-1997, Prefabricated Plastic Spa Shells; IBR approved for § 3280.604(c). (16) ANSI Z-124.9-1994, Plastic Urinal Fixtures; IBR approved for § 3280.604(c). (i) American Society of Civil Engineers (ASCE), 1801 Alexander Bell Drive, Reston, VA 20191; telephone: 800-548-2723; website: www.asce.org. (1) ANSI/ASCE 7-88, Minimum Design Loads for Buildings and Other Structures, IBR approved for §§ 3280.5(f); 3280.304(b); 3280.305(c). (2) SEI/ASCE 8-02, Specification for the Design of Cold-Formed Stainless Steel Structural Members, 2002; IBR approved for §§ 3280.304(b); 3280.305(j). (3) ASCE 19-96, Structural Applications of Steel Cables for Buildings; IBR approved for § 3280.304(b). (j) American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), 1791 Tullie Circle NE, Atlanta, GA 30329; telephone: 404-636-8400; fax: 404-321-5478; website: www.ashrae.org/home/. (1) 1997 ASHRAE Handbook of Fundamentals, chapters 22 through 27, (except for the following parts of this standard that are not incorporated by reference: 23.1 Steel Frame Construction; 23.2 Masonry Construction; 23.3 Foundations and Floor Systems; 23.15 Pipes; 23.17 Tanks, Vessels, and Equipment; 23.18 Refrigerated Rooms and Buildings; 24.18 Mechanical and Industrial Systems; 25.19 Commercial Building Envelope Leakage; 27.9 Calculation of Heat Loss from Crawl Spaces), Inch-Pound Edition, 1997; IBR approved for §§ 3280.508(a) and (e); 3280.511(a). (2) ANSI/ASHRAE Standard 62.2-2013, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings, approved January 30, 2013 (ANSI/ASHRAE 62.2); IBR approved for §§ 3280.103(d) and (e); 3280.703(d). (k) American Society of Mechanical Engineers (ASME), Two Park Avenue, New York, NY 10016-5990; telephone: 800-843-2763; website: www.asme.org/. (1) ASME A112.1.2-1991, Air Gaps in Plumbing Systems; IBR approved for § 3280.604(c). (2) ANSI/ASME A112.4.1-1993, Water Heater Relief Valve Drain Tubes; IBR approved for § 3280.604(c). (3) ANSI/ASME A112.4.3-1999, Plastic Fittings for Connecting Water Closets to the Sanitary Drainage System; IBR approved for § 3280.604(c). (4) ASME/ANSI A112.18.1M-1989, Plumbing Fixture Fittings; IBR approved for § 3280.604(c). (5) ASME A112.18.3M-1996, Performance Requirements for Backflow Protection Devices and Systems in Plumbing Fixture Fittings; IBR approved for § 3280.604(c). (6) ASME A112.18.6-1999, Flexible Water Connectors; IBR approved for § 3280.604(c). (7) ASME A112.18.7-1999, Deck Mounted Bath/Shower Transfer Valves with Integral Backflow Protection; IBR approved for § 3280.604(c). (8) ANSI/ASME A112.19.1M-1987, Enameled Cast Iron Plumbing Fixtures; IBR approved for § 3280.604(c). (9) ANSI/ASME A112.19.2(M)-1990, Vitreous China Plumbing Fixtures; IBR approved for § 3280.604(c). (10) ANSI/ASME A112.19.3M-1987, Stainless Steel Plumbing Fixtures (Designed for Residential Use); IBR approved for § 3280.604(c). (11) ANSI/ASME A112.19.4(M)-1984, Porcelain Enameled Formed Steel Plumbing Fixtures; IBR approved for § 3280.604(c). (12) ASME A112.19.6-1995, Hydraulic Performance Requirements for Water Closets and Urinals; IBR approved for § 3280.604(c). (13) ASME/ANSI A112.19.7M-1987, Whirlpool Bathtub Appliances; IBR approved for § 3280.604(c). (14) ASME/ANSI A112.19.8M-1989, Suction Fittings for Use in Swimming Pools, Wading Pools, Spas, Hot Tubs, and Whirlpool Bathtub Appliances; IBR approved for § 3280.604(c). (15) ASME A112.19.9M-1991, Non-Vitreous Ceramic Plumbing Fixtures; IBR approved for § 3280.604(c). (16) ASME A112.19.10-1994, Dual Flush Devices for Water Closets; IBR approved for § 3280.604(c). (17) ANSI/ASME A112.21.3M-1985, Hydrants for Utility and Maintenance Use; IBR approved for § 3280.604(c). (18) ANSI/ASME B1.20.1-2013, Pipe Threads, General Purpose (Inch), reaffirmed 2018; IBR approved for §§ 3280.604(c); 3280.703(b); 3280.705(e); 3280.706(d). (19) ANSI/ASME B16.3-1992, Malleable Iron Threaded Fittings; IBR approved for § 3280.604(c). (20) ANSI/ASME B16.4-1992, Gray Iron Threaded Fittings; IBR approved for § 3280.604(c). (21) ANSI/ASME B16.15-1985, Cast Bronze Threaded Fittings, Classes 125 and 250; IBR approved for § 3280.604(c). (22) ASME/ANSI B16.22-1989, Wrought-Copper and Copper Alloy Solder-Joint Pressure Fitting; IBR approved for § 3280.604(c). (23) ASME B16.23-1992, Cast Copper Alloy Solder-Joint Drainage Fittings-DWV; IBR approved for § 3280.604(c). (24) ASME/ANSI B16.26-1988, Cast Copper Alloy Fittings for Flared Copper Tubes; IBR approved for § 3280.604(c). (25) ASME/ANSI B16.29-1986, Wrought Copper and Wrought Copper Alloy Solder-Joint Drainage Fittings-DWV; IBR approved for § 3280.604(c). (26) ANSI/ASME B36.10-2004, Welded and Seamless Wrought Steel Pipe, ANSI-approved June 23, 2004; IBR approved for §§ 3280.604(c); 3280.703(b), 3280.705(b); 3280.706(b). (l) American Society of Sanitary Engineering (ASSE), 901 Canterbury, Suite A, Westlake, OH 44145; telephone: 440-835-3040; fax: 440-835-3488; website: www.asse-plumbing.org. (1) ASSE 1001, Performance Requirements for Pipe Applied Atmospheric Type Vacuum Breakers, ANSI-approved 1990; IBR approved for § 3280.604(c). (2) ASSE 1002 (ANSI/ASSE-1979), Performance Requirements for Water Closet Flush Tank Fill Valves (Ballcocks), Revision 5, 1986; IBR approved for § 3280.604(c). (3) ASSE 1006, Plumbing Requirements for Residential Use (Household) Dishwashers, ASSE/ANSI-1986; IBR approved for § 3280.604(c). (4) ASSE 1007-1986, Performance Requirements for Home Laundry Equipment; IBR approved for § 3280.604(c). (5) ASSE 1008-1986, Performance Requirements for Household Food Waste Disposer Units; IBR approved for § 3280.604(c). (6) ASSE 1011-1981, Performance Requirements for Hose Connection Vacuum Breakers, ANSI-approved 1982; IBR approved for § 3280.604(c). (7) ASSE 1014-1989, Performance Requirements for Hand-held Showers, ANSI-approved 1990; IBR approved for § 3280.604(c). (8) ASSE 1016-2005, Performance Requirements for Automatic Compensating Values for Individual Shower and Tub/Shower Combinations, approved January 2005; IBR approved for §§ 3280.604(c); 3280.607(b). (9) ASSE 1017-1986, Performance Requirements for Temperature Activated Mixing Valves for Primary Domestic Use, 1986; IBR approved for § 3280.604(c). (10) ANSI/ASSE 1019-1978, Performance Requirements for Wall Hydrants, Frost Proof Automatic Draining, Anti-Backflow Types, 1978; IBR approved for § 3280.604(c). (11) ASSE 1023, Performance Requirements for Hot Water Dispensers, Household Storage Type Electrical, ANSI/ASSE-1979; IBR approved for § 3280.604(c). (12) ASSE 1025, Performance Requirements for Diverters for Plumbing Faucets with Hose Spray, Anti-Siphon Type, Residential Applications, ANSI/ASSE-1978; IBR approved for § 3280.604(c). (13) ASSE 1037-1990, Performance Requirements for Pressurized Flushing Devices (Flushometers) for Plumbing Fixtures, ANSI-approved 1990; IBR approved for § 3280.604(c). (14) ASSE 1051, Performance Requirements for Air Admittance Valves for Plumbing Drainage Systems—Fixture and Branch Devices Revised 1996, ANSI-approved 1998; IBR approved for § 3280.604(c). (15) ASSE 1070-2004, Performance Requirements for Water Temperature Limiting Devices, 2004; IBR approved for §§ 3280.604(c); 3280.607(b). (m) APA—The Engineered Wood Association (APA) (formerly the American Plywood Association), 7011 South 19th Street, Tacoma, WA 98411; telephone: 253-565-6600; fax: 253-565-7265; website: www.apawood.org. (1) APA D510C, Panel Design Specification, copyright 2012; IBR approved for § 3280.304(b). (2) APA E30P-1996, APA Design/Construction Guide, Residential and Commercial Structures; IBR approved for § 3280.304(b). (3) APA E30V, Engineered Wood Construction Guide, copyright 2011; IBR approved for § 3280.304(b). (4) APA H815G, Plywood Design Specification Supplement 5-12, Design and Fabrication of All-Plywood Beams, December 2013; IBR approved for § 3280.304(b). (5) APA S811P, Plywood Design Specification Supplement 1-12, Design and Fabrication of Plywood Curved Panels, December 2013; IBR approved for § 3280.304(b). (6) APA S812S, Plywood Design Specification Supplement 2-12, Design and Fabrication of Glued Plywood-Lumber Beams, December 2013; IBR approved for § 3280.304(b). (7) APA U813M, Plywood Design Specification Supplement 3-12, Design and Fabrication of Plywood Stressed-Skin Panels, December 2013; IBR approved for § 3280.304(b). (8) APA U814J, Plywood Design Specification Supplement 4-12, Design and Fabrication of Plywood Sandwiched Panels, December 2013; IBR approved for § 3280.304(b). (9) APA Y510, Plywood Design, January 1997; IBR approved for § 3280.304(b). (n) ASTM, International (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959; telephone:877-909-2786 (USA & Canada); fax: 610-832-9555; website: www.astm.org. (1) ASTM A53/A53M-12, Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless, approved March 1, 2012; IBR approved for §§ 3280.604(c); 3280.703(b). (2) ASTM A74-92, Standard Specification for Cast Iron Soil Pipe and Fittings, 1992; IBR approved for § 3280.604(c). (3) ASTM A539-99, Standard Specification for Electric-Resistance-Welded Coiled Steel Tubing for Gas and Fuel Oil Lines, 1999; IBR approved for §§ 3280.703(b); 3280.705(b); 3280.706(b). (4) ASTM B42-10, Standard Specification for Seamless Copper Pipe, Standard Sizes, approved October 1, 2010; IBR approved for §§ 3280.604(c); 3280.703(c). (5) ASTM B43-91, Standard Specification for Seamless Red Brass Pipe, Standard Sizes, 1991; IBR approved for §§ 3280.604(c); 3280.705(b). (6) ASTM B88-14, Standard Specification for Seamless Copper Water Tube, approved September 1, 2014; IBR approved for §§ 3280.604(c); 3280.703(c); 3280.705(b); 3280.706(b). (7) ASTM B251-10, Standard Specification for General Requirements for Wrought Seamless Copper and Copper-Alloy Tube, approved October 1, 2010; IBR approved for §§ 3280.604(c); 3280.703(c). (8) ASTM B280-13, Standard Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service, approved April 1, 2013; IBR approved for §§ 3280.703(c); 3280.705(b); 3280.706(b). (9) ASTM B306-92, Standard Specification for Copper Drainage Tube (DWV), 1992; IBR approved for § 3280.604(c). (10) ASTM C564-97, Standard Specification for Rubber Gaskets for Case Iron Soil Pipe and Fittings, approved December 10, 1997; IBR approved for §§ 3280.604(c); 3280.611(d). (11) ASTM C920-02, Standard Specification for Elastomeric Joint Sealants, approved January 10, 2002; IBR approved for § 3280.611(d). (12) ASTM C1396/C1396M-14a, Standard Specification for Gypsum Board, approved October 1, 2014; IBR approved for § 3280.304(b). (13) ASTM D781-68 (Reapproved 1973), Standard Test Methods for Puncture and Stiffness of Paperboard, and Corrugated and Solid Fiberboard, 1973; IBR approved for §§ 3280.304(b); 3280.305(g). (14) ASTM D2235-88, Standard Specification for Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe and Fittings, 1988; IBR approved for § 3280.604(c). (15) ASTM D2564-91a, Standard Specification for Solvent Cements for Poly (Vinyl Chloride) (PVC) Plastic Piping Systems, 1991; IBR approved for § 3280.604(c). (16) ASTM D2661-91, Standard Specification for Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40 Plastic Drain, Waste, and Vent Pipe and Fittings, 1991; IBR approved for § 3280.604(c). (17) ASTM D2665-91b, Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Drain, Waste, and Vent Pipe and Fittings, 1991; IBR approved for § 3280.604(c). (18) ASTM D2846-92, Standard Specification for Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Hot- and Cold-Water Distribution Systems, 1992; IBR approved for § 3280.604(c). (19) ASTM D3309-92a, Standard Specification for Polybutylene (PB) Plastic Hot- and Cold-Water Distribution Systems, 1992; IBR approved for § 3280.604(c). (20) ASTM D3311-92, Standard Specification for Drain, Waste, and Vent (DWV) Plastic Fittings Patterns, 1992; IBR approved for § 3280.604(c). (21) ASTM D3679-09a, Standard Specification for Rigid Poly (Vinyl Chloride) (PVC) Siding, approved November 1, 2009; IBR approved for §§ 3280.304(b); 3280.309(b). (22) ASTM D3953-97, Standard Specification for Strapping, Flat Steel, and Seals, approved April 10, 1997; IBR approved for §§ 3280.304(b); 3280.306(g). (23) ASTM D4442-07, Standard Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials, approved November 15, 2007; IBR approved for § 3280.304(b). (24) ASTM D4444-13, Standard Test Method for Laboratory Standardization and Calibration of Hand-Held Moisture Meters, approved April 1, 2013; IBR approved for § 3280.304(b). (25) ASTM D4635-01, Standard Specification for Polyethylene Films Made from Low-Density Polyethylene for General Use and Packaging Applications, approved June 10, 2001; IBR approved for § 3280.611(d). (26) ASTM D4756-06, Standard Practice for Installation of Rigid Poly(Vinyl Chloride) (PVC) Siding and Soffit, approved April 1, 2006; IBR approved for §§ 3280.304(b); 3280.309(c). (27) ASTM D6007-14, Standard Test Method for Determining Formaldehyde Concentrations in Air from Wood Products Using a Small Air Chamber, approved October 1, 2014; IBR approved for § 3280.406(b). (28) ASTM D7254-07, Standard Specification for Polypropylene (PP) Siding, January 1, 2007; IBR approved for §§ 3280.304(b); 3280.309(c). (29) ASTM E84-01, Standard Test Method for Surface Burning Characteristics of Building Materials, 2001; IBR approved for § 3280.203(a). (30) ASTM E90-09, Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements, approved July 1, 2009; IBR approved for § 3280.115(b). (31) ASTM E96/E96M-13, Standard Test Methods for Water Vapor Transmission of Materials, approved November 1, 2013; IBR approved for § 3280.504(a) and (c). (32) ASTM E119-14, Standard Test Methods for Fire Tests of Building Construction and Materials, approved October 1, 2014; IBR approved for §§ 3280.215(a) and (d); 3280.304(b); 3280.1003(a). (33) ASTM E162-94, Standard Test Method for Surface Flammability of Materials Using a Radiant Heat Energy Source, 1994; IBR approved for § 3280.203(a). (34) ASTM E492-09, Standard Test Method for Laboratory Measurement of Impact Sound Transmission Through Floor-Ceiling Assemblies Using the Tapping Machine, approved April 1, 2009; IBR approved for § 3280.115(b). (35) ASTM E773-97, Standard Test Methods for Accelerated Weathering of Sealed Insulating Glass Units, 1997; IBR approved for § 3280.403(d). (36) ASTM E774-97, Standard Specification for the Classification of the Durability of Sealed Insulating Glass Units, 1997; IBR approved for § 3280.403(d). (37) ASTM E814-13, Standard Test Method for Fire Tests of Penetration Firestop Systems, approved November 1, 2013; IBR approved for § 3280.215(d). (38) ASTM E1333-14, Standard Test Method for Determining Formaldehyde Concentrations in Air and Emission Rates from Wood Products Using a Large Air Chamber, approved October 1, 2014; IBR approved for § 3280.406(b). (39) ASTM F628-91, Standard Specification for Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40, Plastic Drain, Waste, and Vent Pipe with a Cellular Core, 1991; IBR approved for § 3280.604(c). (40) ASTM F876-10, Standard Specification for Crosslinked Polyethylene (PEX) Tubing, approved February 10, 2010; IBR approved for § 3280.604(c). (41) ASTM F877-07, Standard Specification for Crosslinked Polyethylene (PEX) Plastic Hot- and Cold-Water Distribution Systems, approved February 1, 2007; IBR approved for § 3280.604(c). (o) American Wood Council (AWC), 222 Catoctin Circle SE, Suite 201, Leesburg, VA 20175; telephone: 202-463-2766; website: www.awc.org. (1) AWC NDS-2015, National Design Specifications for Wood Construction with Supplement; IBR approved for §§ 3280.215(a); 3280.304(b): (i) ANSI/AWC NDS-2015, 2015 Edition, ANSI-approved September 30, 2014; and (ii) NDS Supplement, Design Values for Wood Construction, 2015 Edition, November 2014. (2) Span Tables for Joists and Rafters: American Softwood Lumber Standard (PS 20-10) Sizes, 2012 Edition (AWC-2012—Span Tables for Joists and Rafters); IBR approved for § 3280.304(b). (3) Design Values for Joists and Rafters, Supplement to Span Tables for Joists and Rafters (2012 Edition), March 2013 (AWC-2012 Design Values for Joists and Rafters); IBR approved for § 3280.304(b). (p) Cast Iron Soil Pipe Institute (CISPI), 1064 Delaware Avenue SE, Atlanta, GA 30316; telephone: 404-622-0073; fax: 404-973-2845; website: www.cispi.org/. (1) CISPI-301-90, Standard Specification for Hubless Cast Iron Soil Pipe and Fittings for Sanitary and Storm Drain, Waste, and Vent Piping Applications; IBR approved for § 3280.604(c). (2) CISPI-HSN-85, Specification for Neoprene Rubber Gaskets for HUB and Spigot Cast Iron Soil Pipe and Fittings; IBR approved for §§ 3280.604(c), 3280.611(d). (q) Composite Panel Association (formerly the American Hardboard Association), 19465 Deerfield Ave, Suite 306, Leesburg, VA 20176; telephone: 703-724-1128; website: compositepanel.org. (1) ANSI A135.4-2012, Basic Hardboard, approved June 8, 2012; IBR approved for § 3280.304(b). (2) ANSI A135.5-2012, Prefinished Hardboard Paneling, approved March 29, 2012; IBR approved for § 3280.304(b). (3) ANSI A135.6-2012 (R2020), Engineered Wood Siding, Reaffirmation approved March 13, 2020; IBR approved for § 3280.304(b). (4) ANSI A208.1-2009, Particleboard, approved February 2, 2009; IBR approved for § 3280.304(b). (r) CSA Group, formerly known as the Canadian Standards Association (CSA), 178 Rexdale Boulevard, Toronto, ON, M9W 1R3, Canada; telephone: 216-524-4990; website: www.csagroup.org. (1) AAMA/WDMA/CSA 101/I.S.2/A440-17, North American Fenestration Standard/Specification for Windows, Doors, and Skylights, revised September 2018; IBR approved for §§ 3280.304(b); 3280.403(b) and (e); 3280.404(b) and (e); 3280.405(b) and (e). (2) ANSI LC 1-2014/CSA 6.26-2014, Fuel gas piping systems using corrugated stainless steel tubing, Published March 2014 (ANSI LC 1); IBR approved for § 3280.705(b). (3) ANSI Z21.1-2016/CSA 1.1-2016, household cooking gas appliances, Published February 2016 (ANSI Z21.1); IBR approved for § 3280.703(a). (4) ANSI Z21.5.1-2015/CSA 7.1-2015, gas clothes dryers, volume I, type 1 clothes dryers, Published January 2015 (ANSI Z21.5.1); IBR approved for § 3280.703(a). (5) ANSI Z21.10.1-2014/CSA 4.1-2014, Gas water heaters, volume I, storage water heaters with input ratings of 75,000 BTU per hour or less, Published November 2014 (ANSI Z21.10.1); IBR approved for §§ 3280.703(a); 3280.707(d). (6) ANSI Z21.10.3-2014/CSA 4.3-2014, Gas-fired water heaters, volume III, storage water heaters with input ratings above 75,000 BTU per hour, circulating and instantaneous, Published August 2014 (ANSI Z21.10.3); IBR approved for § 3280.703(a). (7) ANSI Z21.15-2009 (reaffirmed 2019)/CSA 9.1-2009 (reaffirmed 2019), American National Standard/CSA Standard for Manually Operated Gas Valves for Appliances, Appliance Connector Valves and Hose End Valves, Second Edition—2009, Published July 2009 (ANSI Z21.15); IBR approved for §§ 3280.703(c); 3280.705(c) and (l). (8) ANSI Z21.19-2014/CSA1.4-2014, Refrigerators using gas fuel, Published May 2014 (ANSI Z21.19); IBR approved for § 3280.703(a). (9) ANSI Z21.20-2014 (reaffirmed 2019)/CAN/CSA C22.2 No.60730-2-5-14 (reaffirmed 2019), Automatic electrical controls for household and similar use—Part 2-5: Particular requirements for automatic electrical burner control systems, Reprinted September 30, 2019 (ANSI Z21.20); IBR approved for § 3280.703(d). (10) ANSI Z21.21-2012/CSA 6.5-2012, Automatic valves for gas appliances, Fourth Edition—2012, Published November 2012 (ANSI Z21.21); IBR approved for § 3280.703(d). (11) ANSI Z21.23, Gas Appliance Thermostats and addenda; IBR approved for § 3280.703(d): (i) ANSI Z21.23-2000, Tenth Edition—2000, ANSI-approved September 27, 2000; (ii) ANSI Z21.23a-2003, Addenda to the Tenth Edition of Gas Appliance Thermostats, ANSI-approved September 17, 2003; and (iii) ANSI Z21.23b-2005, Addenda to the Tenth Edition of ANSI Z21.23-2000 and Addenda Z21.23a-2003: Gas Appliance Thermostats, ANSI-approved March 9, 2005. (12) ANSI Z21.24-2006/CSA 6.10-2006 (reaffirmed 2011), Connectors for Gas Appliances, Third Edition—2006, Published February 2007 (ANSI Z21.24); IBR approved for § 3280.703(c). (13) ANSI Z21.40.1-1996/CGA 2.91-M96, Gas-Fired, Heat Activated Air Conditioning and Heat Pump Appliances); IBR approved for §§ 3280.703(a); 3280.714(a). (14) ANSI Z21.47-2012/CSA 2.3-2012, Gas-fired central furnaces, Sixth Edition—2012, ANSI-approved March 27, 2012 (ANSI Z21.47); IBR approved for § 3280.703(a). (15) ANSI Z21.75-2007/CSA 6.27-2007 (reaffirmed 2012), Connectors for Outdoor Gas Appliances And Manufactured Homes, Second Edition, Published 2007 (ANSI Z21.75); IBR approved for § 3280.703(a). (s) Decorative Hardwoods Association (formerly HPVA), 42777 Trade West Drive, Sterling, VA 20166; telephone: 703-435-2900; fax: 703-435-2537; website: www.decorativehardwoods.org. (1) ANSI/HPVA HP-1-2009, American National Standard for Hardwood and Decorative Plywood, approved January 26, 2010; IBR approved for § 3280.304(b). (2) HP-SG-96, Structural Design Guide for Hardwood Plywood Wall Panels, revised 1996; IBR approved for § 3280.304(b). (t) FS—Federal Specifications, General Services Administration, Specifications Branch, Room 6039, GSA Building, 7th and D Streets SW, Washington, DC 20407. (1) FS WW-P-541E/GEN-1980, Plumbing Fixtures (General Specifications); IBR approved for § 3280.604(c). (2) FS ZZ-R-765B-1970, Silicone Rubber, (with 1971 Amendment); IBR approved for § 3280.611(d). (3) TT-P-1536A, Plumbing Fixture Setting Compound, July 8, 1975; IBR approved for § 3280.604(b). (u) Fenestration and Glazing Industry Alliance (FGIA) (formerly known as American Architectural Manufacturers Association (AAMA)), 1900 E Golf Road, Schaumburg, Illinois 60173; website: www.fgiaonline.org. (1) AAMA 1503.1-88, Voluntary Test Method for Thermal Transmittance and Condensation Resistance of Windows, Doors, and Glazed Wall Sections; IBR approved for § 3280.508(e). (2) AAMA 1600/I.S.7-00, Voluntary Specification for Skylights, 2003; IBR approved for § 3280.305(c). (3) AAMA 1701.2-12, Voluntary Standard for Utilization in Manufactured Housing for Primary Windows and Sliding Glass Doors, published November 2012; IBR approved for §§ 3280.403(b) and (e); 3280.404(b) and (e). (4) AAMA 1702.2-12, Voluntary Standard for Utilization in Manufactured Housing for Swinging Exterior Passage Doors, published November 2012, including errata dated February 16, 2015 and March 29, 2017; IBR approved for §§ 3280.403(e); 3280.405(b) and (e). (5) AAMA 1704-12, Voluntary Standard Egress Window Systems for Utilization in Manufactured Housing, published November 2012; IBR approved for § 3280.404(b) and (e). (v) HUD User, 11491 Sunset Hills Road, Reston, VA 20190-5254; telephone: 800-245-2691; website: www.huduser.gov. (1) HUD User No. 0005945, Overall U-values and Heating/Cooling Loads—Manufactured Homes, February 1992; IBR approved for § 3280.508(b). (2) [Reserved] (w) IIT Research Institute (IITRI), 10 West 35th Street, Chicago, IL 60616; telephone: 312-567-4000; website: www.iitri.org/. (1) IITRI Fire and Safety Research Project J-6461 “Development of Mobile Home Fire Test Methods to Judge the Fire-Safe Performance of Foam Plastic Sheathing and Cavity Insulation”, 1979; IBR approved for § 3280.207(a). (2) [Reserved] (x) International Association of Plumbing and Mechanical Officials (IAPMO), 4755 East Philadelphia Street, Ontario, CA 91716; telephone: 909-472-4100; fax: 909-472-4150; website: www.iapmo.org. (1) IAPMO PS 2-89, Material and Property Standard for Cast Brass and Tubing P-Traps. 1989; IBR approved for § 3280.604(c). (2) IAPMO PS 4-90, Material and Property Standard for Drains for Prefabricated and Precast Showers, 1990; IBR approved for § 3280.604(c). (3) IAPMO PS 5-84, Material and Property Standard for Special Cast Iron Fittings, 1984; IBR approved for § 3280.604(c). (4) IAPMO PS 9-84, Material and Property Standard for Diversion Tees and Twin Waste Elbow, 1984; IBR approved for § 3280.604(c). (5) IAPMO PS 14-89, Material and Property Standard for Flexible Metallic Water Connectors, 1989; IBR approved for § 3280.604(c). (6) IAPMO PS 23-89, Material and Property Standard for Dishwasher Drain Airgaps, 1989; IBR approved for § 3280.604(c). (7) IAPMO PS 31-91, Material and Property Standards for Backflow Prevention Assemblies, 1989; IBR approved for § 3280.604(c). (8) IAPMO TS 9-2003, Standard for Gas Supply Connectors for Manufactured Homes, revised 2003; IBR approved for § 3280.703(c). (9) IAPMO TSC 22-85, Standard for Porcelain Enameled Formed Steel Plumbing Fixtures; IBR approved for § 3280.604(c). (y) International Code Council Evaluation Service (ICC-ES), 3060 Saturn Street, Suite 100, Brea, CA 92821; telephone: 800-423-6587; fax: 562-695-4694; website: www.icc-es.org. (1) ESR 1539, ICC-ES Evaluation Report; Power Driven Staples and Nails, reissued June 2014; IBR approved for § 3280.304(b). (2) [Reserved] (z) International Organization for Standardization, Chemin de Blandonnet 8, CP 401—1214 Vernier, Geneva, Switzerland; telephone: +41 22 749 01 11; website: www.iso.org. (1) ISO/IEC 17065:2012(E) Conformity assessment—requirements for bodies certifying products, processes and services, approved September 15, 2012; IBR approved for §§ 3280.403(e); 3280.404(e); 3280.405(e). (2) [Reserved] (aa) Military Specifications and Standards, Naval Publications and Forms Center (MIL), 5801 Tabor Avenue, Philadelphia, PA 19120; website: www.dsp.dla.mil/. (1) MIL-L-10547E-1975, Liners, Case, and Sheet, Overwrap; Water-Vapor Proof or Waterproof, Flexible, 1975; IBR approved for § 3280.611(d). (2) [Reserved] (bb) National Electrical Manufacturers Association (NEMA), 1300 North 17th Street, Suite 1752, Arlington, VA 22209; telephone: 703-841-3200; fax: 703-841-5900; website: www.nema.org/Pages/default.aspx. (1) ANSI/NEMA WD-6-1997 Wiring Devices-Dimensional Specifications, 1997; IBR approved for § 3280.803(f). (2) [Reserved] (cc) National Fenestration Rating Council (NFRC), 6305 Ivy Lane, Suite 140, Greenbelt, MD 20770; telephone: 301-589-1776; fax: 301-589-3884; website: www.nfrc.org. (1) NFRC 100, Procedure for Determining Fenestration Product U-factors, 1997 Edition, 1997; IBR approved for § 3280.508(e). (2) [Reserved] (dd) National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA 02269; telephone: 617-770-3000; fax: 617-770-0700; website: www.nfpa.org. (1) NFPA 13D, Standard for the Installation of Sprinkler Systems in One- and Two- Family Dwellings and Manufactured Homes, 2010 Edition, approved August 26, 2009; IBR approved for § 3280.214(b), (e) and (o). (2) NFPA 31, Standard for the Installation of Oil-Burning Equipment, 2011 Edition, approved January 3, 2011; IBR approved for §§ 3280.703(d); 3280.707(f). (3) NFPA 54/ANSI Z223.1, National Fuel Gas Code, 2015 Edition, approved September 3, 2014; IBR approved for § 3280.703(d). (4) NFPA 58, Liquefied Petroleum Gas Code, 2014 Edition, approved August 1, 2013; IBR approved for § 3280.703(d). (5) NFPA 70, National Electrical Code, 2014 Edition, approved August 21, 2013; IBR approved for §§ 3280.607(c); 3280.801(b); 3280.803(k); 3280.804(a) and (k); 3280.805(a); 3280.806(a) and (d); 3280.807(c); 3280.808(a), (l), and (p); 3280.810(b); 3280.811(b). (6) NFPA 90B, Standard for the Installation of Warm Air Heating and Air-Conditioning Systems, 2015 Edition, approved May 19, 2015; IBR approved for § 3280.703(d). (7) NFPA 220, Standard on Types of Building Construction, Chapter 2: definitions of “limited combustible” and “noncombustible material”, 1995 Edition; IBR approved for § 3280.202. (8) NFPA 253, Standard Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source, 2000; IBR approved for § 3280.207(c). (9) NFPA 255, Standard Method of Test of Surface Burning Characteristics of Building Materials, 1996; IBR approved for §§ 3280.203(a); 3280.207(a). (10) NFPA 720, Standard for Installation of Carbon Monoxide Detection (CO) Detection and Warning Equipment, 2015 Edition, Copyright 2014; IBR approved for § 3280.211(b). (ee) U.S. Department of Commerce, National Institute of Standards and Technology (NIST), Office of Engineering Standards, Room A-166, Technical Building, Washington, DC 20234 and Voluntary Product Division, 100 Bureau Drive, Stop 2100, Gaithersburg, MD 20899-2100; telephone: 301-975-4000; fax: 301-975-4715; website: www.nist.gov. (1) Voluntary Product Standard PS 1-09, Structural Plywood (With Typical APA Trademarks), effective May 1, 2009 (NIST PS 1); IBR approved for § 3280.304(b). (2) Voluntary Product Standard PS 2-04, Performance Standard for Wood-Based Structural-Use Panels, December 2004 (NIST PS 2); IBR approval for § 3280.304(b). (ff) National Sanitation Foundation (NSF), 789 North Dixboro Road, Ann Arbor, MI 48105; telephone: 734-769-8010 fax: 734-769-0109; website: www.nsf.org. (1) ANSI/NSF 14-1990, Plastic Piping Components and Related Materials; IBR approved for § 3280.604(c). (2) ANSI/NSF 24-1988, Plumbing System Components for Manufactured Homes and Recreational Vehicles; IBR approved for § 3280.604(c). (3) ANSI/NSF 61-2001, Drinking Water System Components-Health Effects; IBR approved for § 3280.604(b). (gg) Resources, Applications, Designs, & Controls (RADCO), 3220 East 59th Street, Long Beach, CA 90805; telephone: 562-272-7231; fax: 562-529-7513; website: www.radcoinc.com. (1) RADCO DS-010-91, Decorative Gas Appliances for Installation in Solid Fuel Burning Fireplaces, May 1991; IBR approved for § 3280.703(a). (2) [Reserved] (hh) Society of Automotive Engineers (SAE), 400 Commonwealth Drive, Warrendale, PA 15096; telephone: 724-776-0790; website: www.sae.org/. (1) SAE J533 (REV SEP 2007), (R) Flares for Tubing, revised September 2007; IBR approved for §§ 3280.703(d); 3280.705(f). (2) [Reserved] (ii) Steel Joist Institute (SJI), 234 West Cheves Street, Florence, SC 29501; telephone: 843-407-4091; website: www.steeljoist.org. (1) SJI 1994, Standard Specifications Load Tables and Weight Tables for Steel Joists and Girders, Fortieth Edition, 1994; IBR approved for § 3280.304(b). (2) [Reserved] (jj) Truss Plate Institute (TPI), 2670 Crain Highway, Suite 203, Waldorf, MD 20601; telephone: 240-587-5582; fax: 866-501-4012; website: www.tpinst.org. (1) TPI 1, National Design Standard for Metal Plate Connected Wood Truss Construction, Commentary, and Appendices, copyright 2008; IBR approved for § 3280.304(b): (i) ANSI/TPI 1-2007; (ii) TPI 1-2007 Commentary and Appendices. (2) [Reserved] (kk) Underwriters' Laboratories, Inc. (UL), 333 Pfingsten Road, Northbrook, IL 60062; telephone: 847-272-8800; fax: 847-509-6257; website: www.ul.com. (1) UL 94-1996, with 2001 revisions, Test for Flammability of Plastic Materials for Parts in Devices and Appliances, Fifth Edition; IBR approved for § 3280.715(e). (2) UL 103, Standard for Safety, Factory-Built Chimneys for Residential Type and Building Heating Appliances, Eleventh Edition, dated October 15, 2010; IBR approved for § 3280.703(d). (3) UL 109, Tube Fittings for Flammable and Combustible Fluids, Refrigeration Service, and Marine Use, Sixth Edition, dated June 19, 1997, including revisions through January 11, 2005; IBR approved for § 3280.703(d). (4) UL 127-1996, with 1999 revisions, Factory-Built Fireplaces, Seventh Edition; IBR approved for § 3280.703(d). (5) UL 174, Standard for Safety Household Electric Storage Tank Water Heaters, Eleventh Edition, dated April 29, 2004, including revisions through December 15, 2016; IBR approved for § 3280.703(a). (6) UL 181, Standard for Safety Factory-Made Air Ducts and Air Connectors, Eleventh Edition, dated July 25, 2013, including revisions through April 18, 2017; IBR approved for §§ 3280.702, 3280.703(d); 3280.715(a) and (e). (7) UL 181A, Standard for Safety Closure Systems for Use with Rigid Air Ducts, Fourth Edition, dated January 8, 2013, including revisions through March 22, 2017; IBR approved for §§ 3280.703(d); 3280.715(c). (8) UL 181B, Standard for Safety Closure Systems for use with Flexible Air Ducts and Air Connectors, First Edition, 1995, with 1998 revisions; IBR approved for §§ 3280.703(d); 3280.715(c). (9) UL 217, Single and Multiple Station Smoke Alarms, Fifth Edition, dated January 4, 1999; IBR approved for §§ 3280.209(a); 3280.211(a). (10) UL 263, Standard for Safety Fire Tests of Building Construction and Materials, Fourteenth Edition, dated June 21, 2011, including revisions through January 31, 2019; IBR approved for § 3280.215(a) and (d). (11) UL 268, Smoke Detectors for Fire Protective Signaling Systems, Fourth Edition, dated December 30, 1996, including revisions through January 4, 1999; IBR approved for §§ 3280.209(a); 3280.703(a). (12) UL 307A, Liquid Fuel Burning Heating Appliances for Manufactured Homes and Recreational Vehicles, Eighth Edition, dated February 25, 2009; IBR approved for §§ 3280.703(a); 3280.707(f). (13) UL 307B, Gas Burning Heating Appliances for Manufactured Homes and Recreational Vehicles, Fifth Edition, dated October 31, 2006, including revisions through September 17, 2013; IBR approved for § 3280.703(a). (14) UL 311, Roof Jacks for Manufactured Homes and Recreational Vehicles, Eighth Edition, 1994, with 1998 revisions; IBR approved for § 3280.703(d). (15) UL 441, Gas Vents, Tenth Edition, dated March 5, 2010, including revisions through June 12, 2014; IBR approved for § 3280.703(d). (16) UL 499, Standard for Safety Electric Heating Appliances, Fourteenth Edition, dated November 7, 2014, including revisions through February 23, 2017; IBR approved for § 3280.703(a). (17) UL 569, Standard for Safety Pigtails and Flexible Hose Connectors for LP-Gas, 2013; IBR approved for §§ 3280.703(d); 3280.705(l). (18) UL 737, Fireplace Stoves, Eighth Edition, 1996, with 2000 revisions; IBR approved for § 3280.703(d). (19) UL 923 Microwave Cooking Appliances, Fifth Edition, May 23, 2002; IBR approved for § 3280.204(c). (20) UL 1042, Standards for Safety Electric Baseboard Heating Equipment, Fifth Edition, dated August 31, 2009, including revisions through December 14, 2016; IBR approved for § 3280.703(a). (21) UL 1096, Electric Central Air Heating Equipment, Fourth Edition, 1986, with revisions July 16, 1986, and January 30, 1988; IBR approved for § 3280.703(a). (22) UL 1479, Fire Tests of Penetration Firestops, Fourth Edition, dated June 10, 2015; IBR approved for § 3280.215(d). (23) UL 1482, Solid-Fuel Type Room Heaters, Fifth Edition, 1996, with 2000 revisions; IBR approved for § 3280.703(d). (24) UL 2021-1997. Fixed and Location-Dedicated Electric Room Heaters, Second Edition, with 1998 revisions; IBR approved for § 3280.703(a). (25) UL 2034, Standard for Safety Single and Multiple Station Carbon Monoxide Alarms, Fourth Edition, dated March 31, 2017; IBR approved for §§ 3280.209(a); 3280.211(a); 3280.703(a). (26) UL 60335-2-40-2012, Standard for Safety: Household and Similar Electrical Appliances—Part 2-40: Particular Requirements for Electrical Heat Pumps, Air-Conditioners and Dehumidifiers, First Edition, dated November 30, 2012; IBR approved for § 3280.703(a). (ll) Underwriters' Laboratories of Canada (ULC), 7 Underwriters Road, Toronto, Ontario, Canada M1 R 3A9; telephone: 866-937-3852; fax: 416-757-8727; website: www.ul.com/canada/eng/pages/. (1) CAN/ULC S102.2-M88, Standard Method of Test for Surface Burning Characteristics of Floor Coverings and Miscellaneous Materials and Assemblies, Fourth Edition, April 1988; IBR approved for § 3280.207(b). (2) [Reserved] (mm) Window and Door Manufacturers Association (WDMA), 2001 K Street NW, 3rd Floor North, Washington, DC 20006; telephone: 202-367-1157; website: www.wdma.com. (1) WDMA I.S.4-09, Industry Specification for Preservative Treatment for Millwork, copyright 2009; IBR approved for § 3280.405(c). (2) [Reserved] [78 FR 73976, Dec. 9, 2013, as amended at 79 FR 31863, June 3, 2014; 85 FR 5566, Jan. 31, 2020; 86 FR 2516, Jan. 12, 2021; 89 FR 75737, Sept. 16, 2024] § 3280.5 Data plate. Each dwelling unit of a manufactured home must bear a data plate affixed in a permanent manner near the main electrical panel or other readily accessible and visible location. Each data plate shall be made of material what will receive typed information as well as preprinted information, and which can be cleaned of ordinary smudges or household dirt without removing information contained on the data plate; or the data plate shall be covered in a permanent manner with materials that will make it possible to clean the data plate of ordinary dirt and smudges without obscuring the information. Each data plate shall contain not less than the following information: (a) The name and address of the manufacturing plant in which the manufactured home was manufactured. (b) The serial number and model designation of the unit, and the date the unit was manufactured. (c) The applicable statement: This manufactured home is designed to comply with the Federal Manufactured Home Construction and Safety Standards in force at the time of manufacture.or This manufactured home has been substantially completed in accordance with an approved design and has been inspected (except for the components specifically identified in the instructions for completion on-site) in accordance with the Federal Manufactured Home Construction and Safety Standards and the requirements of the Department of Housing and Urban Development (HUD) in effect on the date of manufacture. (d) The applicable statement: This manufactured home IS designed to accommodate the additional loads imposed by the attachment of an attached accessory building or structure in accordance with the manufacturer installation instructions. The additional loads are in accordance with the design load(s) identified on this Data Plate; or This manufactured home IS NOT designed to accommodate the additional loads imposed by the attachment of an attached accessory building or structure in accordance with the manufacturer installation instructions. (e) A list of the certification label(s) number(s) that are affixed to each transportable manufactured section under § 3280.8. (f) A list of major factory-installed equipment, including the manufacturer's name and the model designation of each appliance. (g) Reference to the roof load zone and wind load zone for which the home is designed and duplicates of the maps as set forth in § 3280.305(c). This information may be combined with the heating/cooling certificate and insulation zone map required by §§ 3280.510 and 3280.511. The Wind Zone Map on the Data Plate shall also contain the statement: This home has not been designed for the higher wind pressures and anchoring provisions required for ocean/coastal areas and should not be located within 1500′ of the coastline in Wind Zones II and III, unless the home and its anchoring and foundation system have been designed for the increased requirements specified for Exposure D in ANSI/ASCE 7-88. (h) The statement: This home has—has not—(appropriate blank to be checked by manufacturer) been equipped with storm shutters or other protective coverings for windows and exterior door openings. For homes designed to be located in Wind Zones II and III, which have not been provided with shutters or equivalent covering devices, it is strongly recommended that the home be made ready to be equipped with these devices in accordance with the method recommended in the manufacturers printed instructions. (i) The statement: “Design Approval by”, followed by the name of the agency that approved the design. (j) The statement: The manufacturer certifies this home is compliant with the Title VI, Toxic Substances Control Act. [59 FR 2469, Jan. 14, 1994, as amended at 80 FR 53727, Sept. 8, 2015; 85 FR 5566, Jan. 31, 2020; 86 FR 2516, Jan. 12, 2021; 89 FR 75743, Sept. 16, 2024] § 3280.6 Serial number. (a) A manufactured home serial number which will identify the manufacturer and the state in which the manufactured home is manufactured, must be stamped into the foremost cross member. Letters and numbers must be 3/8 § 3280.7 Excluded structures. Certain structures may be excluded from these Standards as modular homes under 24 CFR 3282.12. [52 FR 4581, Feb. 12, 1987] § 3280.8 Waivers. (a) Where any material piece of equipment, or system which does not meet precise requirements or specifications set out in the standard is shown, to the satisfaction of the Secretary, to meet an equivalent level of performance, the Secretary may waive the specifications set out in the Standard for that material, piece of equipment, or system. (b) Where the Secretary is considering issuing a waiver to a Standard, the proposed waiver shall be published in the Federal Register (c) Each proposed and final waiver shall include: (1) A statement of the nature of the waiver; and (2) Identification of the particular standard affected. (d) All waivers shall be published in the Federal Register Federal Register. [58 FR 55003, Oct. 25, 1993] § 3280.9 Interpretative bulletins. Interpretative bulletins may be issued for the following purposes: (a) To clarify the meaning of the Standard; and (b) To assist in the enforcement of the Standard. [58 FR 55003, Oct. 25, 1993] § 3280.10 Use of alternative construction. Requests for alternative construction can be made pursuant to 24 CFR 3282.14 of this chapter. [58 FR 55003, Oct. 25, 1993] § 3280.11 Certification label. (a) A permanent label shall be affixed to each transportable section of each manufactured home for sale or lease in the United States. This label shall be separate and distinct from the data plate which the manufacturer is required to provide under § 3280.5 of the standards. (b) The label shall be approximately 2 in. by 4 in. in size and shall be permanently attached to the manufactured home by means of 4 blind rivets, drive screws, or other means that render it difficult to remove without defacing it. It shall be etched on 0.32 in. thick aluminum plate. The label number shall be etched or stamped with a 3 letter designation which identifies the production inspection primary inspection agency and which the Secretary shall assign. Each label shall be marked with a 6 digit number which the label supplier shall furnish. The labels shall be stamped with numbers sequentially. (c) The label shall read as follows: As evidenced by this label No. ABC 000001, the manufacturer certifies to the best of the manufacturer's knowledge and belief that this manufactured home has been inspected in accordance with the requirements of the Department of Housing and Urban Development and is constructed in conformance with the Federal manufactured home construction and safety standards in effect on the date of manufacture. See date plate. (d) The label must be located at the taillight end of each transportable section of the manufactured home approximately 1 foot up from the floor and 1 foot in from the road side, or as near that location on a permanent part of the exterior of the manufactured home section as practicable. The road side is the right side of the manufactured home when one views the manufactured home from the tow bar end of the manufactured home. If locating the label on the taillight end of a transportable section will prevent the label from being visible after the manufactured home section is installed at the installation site, the label must be installed on a permanent part of the exterior of the manufactured home section, in a visible location as specified in the approved design. [42 FR 960, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 47553, Dec. 15, 1987. Redesignated and amended at 58 FR 55003, Oct. 25, 1993; 86 FR 2517, Jan. 12, 2021] Subpart B—Planning Considerations § 3280.101 Scope. Subpart B states the planning requirements in manufactured homes. The intent of this subpart is to assure the adequacy of architectural planning considerations which assist in determining a safe and healthful environment. § 3280.102 Definitions. Air, exhaust Air, outdoor Exhaust system Gross floor area Habitable room Laundry area Mechanical ventilation Natural ventilation Supply system Ventilation [89 FR 75744, Sept. 16, 2024] § 3280.103 Light and ventilation. (a) Lighting. (1) Kitchens, bathrooms, toilet compartments, laundry areas, and utility rooms may be provided with artificial light in place of windows. (2) Rooms and areas may be combined for the purpose of providing the required natural lighting provided that at least one half of the common wall area is open and unobstructed, and the open area is at least equal to 10 percent of the combined floor area or 25 square feet whichever is greater. (b) Whole-house ventilation. 3 2 (1) The ventilation capacity must be provided by a mechanical ventilation system or a combination natural and mechanical ventilation system. (2) The ventilation system or provisions for ventilation must exchange air directly with the exterior of the home, except the ventilation system, or provisions for ventilation must not draw or expel air with the space underneath the home. The ventilation system or provisions for ventilation must not draw or expel air into the floor, wall, or ceiling/roof systems, even if those systems are vented. The ventilation system must be designed to ensure that outside air is distributed to all bedrooms and main living areas. The combined use of undercut doors or transom grills connecting those areas to the room where the mechanical system is located is deemed to meet this requirement. (3) The ventilation supply system or a portion of the ventilation supply system is permitted to be integral with the home's heating or cooling system. The supply system must be capable of operating independently of the heating and cooling modes. A mechanical ventilation supply system that is integral with the heating and cooling system is to be listed as part of the heating and cooling system or listed as suitable for use with that system. (4) A mechanical ventilation system, or mechanical portion thereof, must be provided with a manual control, and must be permitted to be provided with automatic timers or humidistats. (5) A whole-house ventilation label must be attached to the whole-house ventilation control, must be permanent, and must state: “WHOLE-HOUSE VENTILATION”. (6) Instructions for correctly operating and maintaining whole-house ventilation systems must be included with the homeowner's manual. The instructions must encourage occupants to operate these systems whenever the home is occupied, and must refer to the labeled whole-house ventilation control. (c) Additional ventilation. (2) Kitchens must be provided with a local exhaust system that is capable of exhausting 100 cfm to the outside of the home. The local exhaust system must be located as close as possible to the range or cook top, but in no case farther than 3 feet horizontally from the range or cooktop. (3) Each bathroom and separate toilet compartment must be provided with a local exhaust system capable of exhausting 50 cfm to the outside of the home. A separate toilet compartment may be provided with 1.5 square feet of openable glazed area in place of a local exhaust system, except in Uo value Zone 3. (d) Optional ventilation provisions. (e) Airflow rating. [58 FR 55003, Oct. 25, 1993, as amended at 70 FR 72042, Nov. 30, 2005; 86 FR 2517, Jan. 12, 2021; 89 FR 75744, Sept. 16, 2024] § 3280.104 Ceiling heights. (a) Every habitable room and bathroom shall have a minimum ceiling height of not less than 7 feet, 0 inches for a minimum of 50 percent of the room's floor area. The remaining area may have a ceiling with a minimum height of 5 feet, 0 inches. Minimum height under dropped ducts, beams, etc. shall be 6 feet, 4 inches. (b) Hallways and foyers shall have a minimum ceiling height of 6 feet, 6 inches. § 3280.105 Exit facilities; exterior doors. (a) Number and location of exterior doors. (1) Required egress doors shall not be located in rooms where a lockable interior door must be used in order to exit. (2) In order for exit doors to be considered remote (i) Both of the required doors must not be in the same room. Rooms are defined by their use or purpose. (ii) Single wide units. (iii) Double wide units. (iv) One of the required exit doors must be accessible from the doorway of each bedroom without traveling more than 35 feet. The travel distance to the exit door must be measured on the floor or other walking surface along the center-line of the natural and unobstructed path of travel starting at the center of the bedroom door, curving around any corners or permanent obstructions with a one-foot clearance from, and ending at, the center of the exit door. (b) Door design and construction. (2) All exterior swinging doors must provide a minimum 28 inch wide by 74 inch high clear opening. Door seals and/or door stops are permitted to reduce the opening, either vertically or horizontally, by a maximum of one inch, except for the one egress door where door seals and/or door stops are not permitted to reduce the opening. All exterior sliding glass doors must provide a minimum 28 inch wide by 72 inch high clear opening. At least one exterior egress door must provide a minimum of 32 inch wide by 74 inch high clear opening and door seals and/or door stops are not permitted to reduce the opening. (3) Each swinging exterior door other than screen or storm doors shall have a key-operated lock that has a deadlocking latch or a key-operated dead bolt with a passage latch. Locks shall not require the use of a key for operation from the inside. (4) All exterior doors, including storm and screen doors, opening outward shall be provided with a safety door check. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 50 FR 9269, Mar. 7, 1985; 78 FR 73981, Dec. 9, 2013; 89 FR 75744, Sept. 16, 2024] § 3280.106 Exit facilities; egress windows and devices. (a) Every room designed expressly for sleeping purposes, unless it has an exit door ( see (b) The bottom of the window opening shall not be more than 36 inches above the floor. (c) Locks, latches, operating handles, tabs, and any other window screen or storm window devices which need to be operated in order to permit exiting, shall not be located in excess of 54 inches from the finished floor. (d) Integral rolled-in screens shall not be permitted in an egress window unless the window is of the hinged-type. [49 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 49 FR 36086, Sept. 14, 1984; 52 FR 4581, Feb. 12, 1987] § 3280.107 Interior privacy. Bathroom and toilet compartment doors shall be equipped with a privacy lock. § 3280.108 Interior passage. (a) Interior doors having passage hardware without a privacy lock, or with a privacy lock not engaged, shall open from either side by a single movement of the hardware mechanism in any direction. (b) Each manufactured home interior door, when provided with a privacy lock, shall have a privacy lock that has an emergency release on the outside to permit entry when the lock has been locked by a locking knob, lever, button, or other locking device on the inside. (c) All interior swinging doors must have a minimum clear opening of 27 inches except doors to toilet compartments in single-section homes (see § 3280.111(b)), and doors to closets and pantries. [40 FR 58752, Dec. 18, 1975, as amended at 86 FR 2517, Jan. 12, 2021] § 3280.109 Room requirements. (a) Each dwelling unit of a manufactured home must have at least one living area with a minimum of 150 square feet of gross floor area. (b) Rooms designed for sleeping purposes shall have a minimum gross square foot floor area as follows: (1) All bedrooms shall have at least 50 sq. ft. of floor area. (2) Bedrooms designed for two or more people shall have 70 sq. ft. of floor area plus 50 sq. ft. for each person in excess of two. (c) Every room designed for sleeping purposes shall have accessible clothes hanging space with a minimum inside depth of 22 inches and shall be equipped with a rod and shelf. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, and further redesignated at 58 FR 55004, Oct. 25, 1993, as amended at 89 FR 75744, Sept. 16, 2024] § 3280.110 Minimum room dimensions. The gross floor area required by § 3280.110 (a) and (b) shall have no clear horizontal dimension less than 5 feet except as permitted by § 3280.102(a). [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, and further redesignated at 58 FR 55004, Oct. 25, 1993] § 3280.111 Toilet compartments. (a) Each toilet compartment must be a minimum of 30 inches wide, except, when the toilet is located adjacent to the short dimension of the tub, the distance from the tub, to the center line of the toilet must not be less than 12 inches. At least 21 inches of clear space must be provided in front of each toilet. (b) All bathroom passage doors in single-section homes must have a minimum clear opening width of 23 inches, and bathroom passage doors in multi-section homes must have a minimum clear opening width of 27 inches. [86 FR 2517, Jan. 12, 2021] § 3280.112 Hallways. Hallways must have a minimum horizontal dimension of 28 inches measured from the interior finished surface to the interior finished surface of the opposite wall. For manufactured homes with 14 feet of inside width or more, hallways must have a minimum horizontal dimension of 30 inches measured from the interior finished surface to the interior finished surface of the opposite wall. When appliances are installed in a laundry area, the measurement must be from the front of the appliance to the opposite finished interior surface. When appliances are not installed and a laundry area is provided, the area must have a minimum clear depth of 27 inches in addition to the 28 inches, or 30 inches for manufactured homes with 14 feet of inside width or greater, required for passage. In addition, a notice of the available clearance for washer/dryer units must be posted in the laundry area. Minor protrusions into the minimum hallway width by doorknobs, trim, smoke alarms or light fixtures are permitted. [89 FR 75744, Sept. 16, 2024] § 3280.113 Glass and glazed openings. (a) Windows and sliding glass doors. (b) Required glazed openings shall be permitted to face into a roofed porch where the porch abuts a street, yard, or court and the longer side of the porch is at least 65 percent open and unobstructed and the ceiling height is not less than 7 feet. (c) Hazardous locations requiring safety glazing. (1) Glazing in all entrance or exit doors; (2) Glazing in fixed and sliding panels of sliding glass doors; (3) Glazing in storm-type doors; (4) Glazing in unframed side-hinged swinging doors; (5) Glazing in doors and fixed panels less than 60 inches above the room floor level that enclose bathtubs, showers, hydromassage tubs, hot tubs, whirlpools, saunas; (6) Glazing within 12 inches horizontally, as measured from the edge of the door in the closed position, and 60 inches vertically as measured from the room floor level, adjacent to and in the same plane of a door; (7) Glazing within 36 inches of an interior room walking surface when the glazing meets all of the following: (i) Individual glazed panels exceed 9 square feet in area in an exposed surface area; (ii) The bottom edge of the exposed glazing is less than 19 inches above the room floor level; and (iii) The top edge of the exposed glazing is greater than 36 inches above the room floor level. (8) Glazing in rails and guardrails; and (9) Glazing in unbacked mirrored wardrobe doors (i.e., mirrors that are not secured to a backing that is capable of being the door itself). (d) Safety glazing is any glazing material capable of meeting the requirements of Consumer Product Safety Commission 16 CFR part 1201, or ANSI Z97.1 (incorporated by reference, see § 3280.4). (e) Glazing in the following locations is not required to meet the requirements in paragraph (b) of this section: (1) Openings in doors through which a 3-inch sphere is unable to pass; (2) Leaded and decorative glazed panels; (3) Glazing in jalousie-type doors; (4) Glazing as described in paragraph (b)(6) of this section when an intervening wall or other permanent barrier exists between the door and the glazing; (5) Glazing as described in paragraph (b)(7) of this section when a protective bar or member is installed horizontally between 34 inches and 38 inches above the room floor level, as long as the bar or member is a minimum of 1 1/2 (6) Mirrors mounted on a flush door surface or solid wall surface. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4581, Feb. 12, 1987. Redesignated at 58 FR 55004, Oct. 25, 1993; 78 FR 73981, Dec. 9, 2013; 86 FR 2517, Jan. 12, 2021; 89 FR 75745, Sept. 16, 2024] § 3280.114 Stairways. (a) Stairways General. (2) Width. 1/2 1/2 (3) Stair treads and risers Riser height and tread depth. 1/4 3/8 3/8 (ii) Profile. 9/16 3/4 1/4 3/4 1/2 (4) Headroom. (5) Winders (winding stairways). 3/8 (6) Spiral stairways. 1/2 1/2 (7) Circular stairways. (b) Landings. (1) There must be a floor or landing at the top and bottom of each stairway, except at the top of an interior flight of basement stairs, provided a door does not swing over the stairs. (2) A landing or floor must be located on each side of an interior doorway and exterior doorway, to the extent the external stairway is designed by the home manufacturer and constructed in the factory, and the width of each landing must not be less than the door it serves. The maximum threshold height above the floor or landing must be 1 1/2 (c) Handrails General. 1/2 (2) Handrail height. (3) Continuity. (4) Graspability. 1/4 1/4 1/4 1/8 1/2 (5) Required resistance of handrails. (d) Guards. (2) Required guards on open sides of stairways, raised floor areas, balconies, and porches must have intermediate rails or ornamental closures that do not allow passage of a sphere 4 inches in diameter. (i) The triangular openings formed by the riser, tread and bottom rail of a guard at the open side of the stairway must be of such a size that a sphere of 6 inches cannot pass through. (ii) Guard systems must be designed to resist a load of 20 lb./ft applied in any direction at the top and to transfer this load through the supports to the structure. All guard systems must be able to resist a single concentrated load of 200 lb., applied in any direction at any point along the top and have attachment devices and supporting structures to transfer this loading to appropriate structural elements of the building. This load is not required to be assumed to act concurrently with the loads specified in this section. (e) Stairway illumination. (1) Interior stairways must be provided with an artificial light source located in the immediate vicinity of each landing of the stairway. For interior stairs, the artificial light sources must be capable of illuminating treads and landings to levels not less than one (1) foot-candle measured at the center of treads and landings. The control and activation of the required interior stairway lighting must be accessible at the top and bottom of each stairway without traversing any steps. (2) Exterior stairways designed by the home manufacturer and constructed in the factory must be provided with an artificial light source located in the immediate vicinity of the top landing of the stairway. An artificial light source is not required at the top and bottom landing, provided an artificial light source is located directly over each stairway section. The illumination of exterior stairways must be controlled from inside the home. [86 FR 2517, Jan. 12, 2021] § 3280.115 Sound transmission between multi-dwelling unit manufactured homes. (a) Scope. (b) Air-borne sound. (c) Structure-borne sound. [89 FR 75745, Sept. 16, 2024] Subpart C—Fire Safety Source: 49 FR 32008, Aug. 9, 1984, unless otherwise noted. § 3280.201 Scope. The purpose of this subpart is to set forth requirements that will assure reasonable fire safety to the occupants by reducing fire hazards and by providing measures for early detection. § 3280.202 Definitions. The following definitions are applicable to subparts C, H, and I of the Standards: Combustible material: Flame-spread rating: Interior finish: (1) Trim and sealant 2 inches or less in width adjacent to the cooking range and in furnace and water heater spaces provided it is installed in accordance with the requirements of § 3280.203(b)(3) or (4), and trim 6 inches or less in width in all other areas; (2) Windows and frames; (3) Single doors and frames and a series of doors and frames not exceeding 5 feet in width; (4) Skylights and frames; (5) Casings around doors, windows, and skylights not exceeding 4 inches in width; (6) Furnishings which are not permanently affixed to the home's structure; (7) Baseboards not exceeding 6 inches in height; (8) Light fixtures, cover plates of electrical receptacle outlets, switches, and other devices; (9) Decorative items attached to walls and partitions (i.e., pictures, decorative objects, etc.) constituting no more than 10% of the aggregate wall surface area in any room or space not more than 32 square feet in surface area, whichever is less; (10) Plastic light diffusers when suspended from a material which meets the interior finish provisions of § 3280.203(b); (11) Coverings and surfaces of exposed wood beams; and (12) Decorative items including the following: (i) Non-structural beams not exceeding 6 inches in depth and 6 inches in width and spaced not closer than 4 feet on center; (ii) Non-structural lattice work; (iii) Mating and closure molding; and (iv) Other items not affixed to the home's structure. Limited combustible: (1) The definition contained in Chapter 2 of NFPA 220-1995, Standard on Types of Building Construction; or (2) 5/16 Noncombustible material: Smoke alarm: Tactile notification appliance: [58 FR 55004, Oct. 25, 1993, as amended at 67 FR 12817, Mar. 19, 2002; 70 FR 72042, Nov. 30, 2005] § 3280.203 Flame spread limitations and fire protection requirements. (a) Establishment of flame spread rating. (1) Flame-spread rating—76 to 200. (i) .035-inch or thicker high pressure laminated plastic panel countertop; (ii) 1/4 (iii) Unfinished dimension lumber (1-inch or thicker nominal boards); (iv) 3/8 (v) Natural gum-varnished or latex- or alkyd-painted: (A) 1/4 (B) 3/8 (C) 1-inch or thicker nominal board; (vi) 5/16 (vii) 1/4 (2) Flame-spread rating-25 to 200, (i) Painted metal; (ii) Mineral-base acoustic tile; (iii) 5/16 (iv) Ceramic tile. (The above-listed material applications do not waive the requirements of § 3280.203(c) or § 3280.204 of this subpart.) (b) Flame-spread rating requirements. (1) The interior finish of all walls, columns, and partitions shall not have a flame spread rating exceeding 200 except as otherwise specified herein. (2) Ceiling interior finish shall not have a flame spread rating exceeding 75. (3) Walls adjacent to or enclosing a furnace or water heater and ceilings above them shall have an interior finish with a flame spread rating not exceeding 25. Sealants and other trim materials 2 inches or less in width used to finish adjacent surfaces within these spaces are exempt from this provision provided that all joints are completely supported by framing members or by materials having a flame spread rating not exceeding 25. (4) Exposed interior finishes adjacent to the cooking range shall have a flame spread rating not exceeding 50, except that backsplashes not exceeding 6 inches in height are exempted. Adjacent surfaces are the exposed vertical surfaces between the range top height and the overhead cabinets and/or ceiling and within 6 horizontal inches of the cooking range. (Refer also to § 3280.204(a), Kitchen Cabinet Protection.) Sealants and other trim materials 2 inches or less in width used to finish adjacent surfaces are exempt from this provision provided that all joints are completely supported by a framing member. (5) Kitchen cabinet doors, countertops, backsplashes, exposed bottoms, and end panels shall have a flame spread rating not to exceed 200. Cabinet rails, stiles, mullions, and top strips are exempted. (6) Finish surfaces of plastic bathtubs, shower units, and tub or shower doors shall not exceed a flame spread rating of 200. (c) Fire protective requirements. (1) Materials used to surface the following areas shall be of limited combustible material (e.g., 5/16 (i) The exposed wall adjacent to the cooking range (see § 3280.203(b)(4)); (ii) Exposed bottoms and sides of kitchen cabinets as required by § 3280.204 except that non-horizontal surfaces above the horizontal plane formed by the bottom of the range hood are not considered exposed; (iii) Interior walls and ceilings enclosing furnace and/or water heater spaces; and (iv) Combustible doors which provide interior or exterior access to furnace and/or water heater spaces. The surface may be interrupted for louvers ventilating the enclosure. However, the louvers shall not be constructed of a material of greater combustibility than the door itself (e.g., plastic louvers on a wooden door). (2) No burner of a surface cooking unit shall be closer than 12 horizontal inches to a window or an exterior door with glazing. [49 FR 32008, Aug. 9, 1984, as amended at 58 FR 55005, Oct. 25, 1993; 70 FR 72042, Nov. 30, 2005; 89 FR 75745, Sept. 16, 2024] § 3280.204 Kitchen cabinet protection. (a) The exposed bottom and sides of combustible kitchen cabinets over cooking ranges to a horizontal distance of 6 inches from the outside edge of the cooking range must be protected with at least 5/16 5/16 3/8 (b) The 3-inch metal eyebrow required by paragraph (a) of this section will project from the front and rear cabinet faces when there is no adjacent surface behind the range, or the 5/16 (c) Alternative compliance. 5/16 3/8 (1) A microwave oven is installed between the cabinet and the range; and (2) The microwave oven is equivalent in fire protection to the metal range hood required by paragraph (a) of this section; and (3) The microwave oven is certified to be in conformance with Microwave Cooking Appliances, UL 923-2002 (incorporated by reference, see § 3280.4). (d) When a manufactured home is designed for the future installation of a cooking range, the metal hood and cabinet protection required by paragraph (a) of this section and the wall-surfacing protection behind the range required by § 3280.203 shall be installed in the factory. (e) Vertical clearance above cooking top. Ranges shall have a vertical clearance above the cooking top of not less than 24 inches to the bottom of combustible cabinets. (f) Range hood finish materials must be installed with at least 5/16 [49 FR 32008, Aug. 9, 1984, as amended at 78 FR 73982, Dec. 9, 2013; 89 FR 75745, Sept. 16, 2024] § 3280.205 Carpeting. Carpeting shall not be used in a space or compartment designed to contain only a furnace and/or water heater. Carpeting may be used in other areas where a furnace or water heater is installed, provided that it is not located under the furnace or water heater. § 3280.206 Fireblocking. (a) General. (b) Fireblocking materials. (1) Minimum one inch nominal lumber, 5/16 (2) Other Listed or Approved Materials; (c) Fireblocking locations. (2) Fireblocking must be installed at the interconnection of a concealed vertical space and a concealed horizontal space that occurs: (i) Between a concealed wall cavity and the ceiling joists above; and (ii) At soffits, drop ceilings, cover ceilings, and similar locations. (3) Fireblocking must be installed around the openings for pipes, vents, and other penetrations in walls, floors, and ceilings of furnace and water heater spaces. Pipes, vents, and other penetrations that cannot be moved freely within their opening are considered to be fireblocked. Materials used to fireblock heat producing vent penetrations must be noncombustible or limited combustible types. [71 FR 72042, Nov. 30, 2005] § 3280.207 Requirements for thermal insulating materials. (a) General. (1) Coverings and facings of insulation batts or blankets installed in concealed spaces when the facings are in substantial contact with the unexposed surface of wall, floor, or ceiling finish; or (2) Cellulose loose-fill insulation that complies with paragraph (b) of this section. (b) Loose-fill insulation. (2) Other loose-fill insulation that cannot be mounted in the NFPA 255-96, test apparatus without a screen or other artificial support must be tested in accordance with CAN/ULC S102.2-M88, Standard Method of Test for Surface Burning Characteristics of Floor Coverings and Miscellaneous Materials and Assemblies (incorporated by reference, see § 3280.4), and must have a flame spread index of 25 or less and a smoke developed index of 450 or less. (c) Attic locations. 2 § 3280.208 Requirements for foam plastic thermal insulating materials. (a) General. (1) The foam plastic insulating material is protected by an interior finish of 5/16 (2) The foam plastic is used as a sheathing or siding backerboard, and it: (i) Has a flame spread rating of 75 or less and a smoke-developed rating of 450 or less (not including outer covering of sheathing); (ii) Does not exceed 3/8 (iii) Is separated from the interior of the manufactured home by a minimum of 2 inches of mineral fiber insulation or an equivalent thermal barrier; or (3) The foam plastic insulating material has been previously accepted by the Department for use in wall and/or ceiling cavities of manufactured homes, and it is installed in accordance with any restrictions imposed at the time of that acceptance; or (4) The foam plastic insulating material has been tested as required for its location in wall and/or ceiling cavities in accordance with testing procedures described in the Illinois Institute of Technology Research Institute (IIT) Report, “Development of Mobile Home Fire Test Methods to Judge the Fire-Safe Performance of Foam Plastic Sheathing and Cavity Insulation, IITRI Fire and Safety Research Project J-6461, 1979” or other full-scale fire tests accepted by HUD, and it is installed in a manner consistent with the way the material was installed in the foam plastic test module. The materials must be capable of meeting the following acceptance criteria required for their location: (i) Wall assemblies. (A) Time to reach flashover (600 °C in the upper part of the room); (B) Time to reach an oxygen (O 2 2 2 (C) Rate of change concentration for O 2 2 (ii) Ceiling assemblies. (iii) Post-test damage assessment for wall and ceiling assemblies. (b) All foam plastic thermal insulating materials used in manufactured housing shall have a flame spread rating of 75 or less (not including outer covering or sheathing) and a maximum smoke-developed rating of 450. [49 FR 32008, Aug. 9, 1984, as amended at 70 FR 72043, Nov. 30, 2005. Redesignated at 78 FR 73982, Dec. 9, 2013] § 3280.209 Smoke alarm requirements. (a) Labeling. (b) Combination alarms. (c) Required smoke alarm locations. (i) To protect both the living area and kitchen space. Manufacturers are encouraged to locate the alarm in the living area remote from the kitchen and cooking appliances. A smoke alarm located within 20 feet horizontally of a cooking appliance must incorporate a temporary silencing feature or be of a photoelectric type. (ii) In each room designed for sleeping. (iii) On the ceiling of the upper level near the top or above each stairway, other than a basement stairway, in any multistory home completed in accordance with this part or part 3282 of this chapter. The alarm must be located so that smoke rising in the stairway cannot be prevented from reaching the alarm by an intervening door or obstruction. (2) For each home designed to be placed over a basement, the manufacturer must provide a smoke alarm for the basement and must install at the factory an electrical junction box for the installation of this smoke alarm and for its interconnection to other smoke alarms required by this section. The instructions for installers and information for homeowners required in paragraph (f) of this section must clearly indicate that a smoke alarm should be installed and is to be located on the basement ceiling near the stairway. (3) A smoke alarm required under this section must not be placed in a location that impairs its effectiveness or in any of the following locations: (i) Within 3 feet horizontally from any discharge grille when a home is equipped or designed for future installation of a roof-mounted evaporative cooler or other equipment discharging conditioned air through a ceiling grille into the living space; and (ii) In any location or environment that is prohibited by the terms of its listing, except as permitted by this section. (d) Mounting requirements. (i) On the ceiling at least 4 inches from each wall; or (ii) On a wall with the top of the alarm not less than 4 inches below the ceiling, and not farther from the ceiling than 12 inches or the distance from the ceiling specified in the smoke alarm manufacturer's listing and instructions, whichever is less. (2) Except as permitted pursuant to paragraph (e) of this section, in rooms with peaked sloping ceilings with a slope of more than 1.5/12, smoke alarms must be mounted on the ceiling within 3 feet, measured horizontally, from the peak of the ceiling; at least 4 inches, measured vertically, below the peak of the ceiling; and at least 4 inches from any projecting structural element. (3) Except as permitted pursuant to paragraph (e) of this section, in rooms with shed sloping ceilings with a slope of more than 1.5/12, smoke alarms must be mounted on the ceiling within 3 feet, measured horizontally, of the high side of the ceiling, and not closer than 4 inches from any adjoining wall surface and from any projecting structural element. (e) Connection to power source. (i) The electrical system of the home as the primary power source and a battery as a secondary power source; or (ii) A battery rated for a 10-year life, provided the smoke alarm is listed for use with a 10-year battery. (2) Each smoke alarm whose primary power source is the home electrical system must be mounted on an electrical outlet box and connected by a permanent wiring method to a general electrical circuit. More than one smoke alarm is permitted to be placed on the same electrical circuit. The wiring circuit for the alarm must not include any switches between the over-current protective device and the alarm, and must not be protected by a ground fault circuit interrupter. (3) Smoke alarms required under this section must be interconnected such that the activation of any one smoke alarm causes the alarm to be triggered in all required smoke alarms in the home. (f) Visible and tactile notification appliances. (2) A visible notification appliance in a room designed for sleeping must have a minimum rating of 177 candela, except that when the visible notification appliance is wall-mounted or suspended more than 24 inches below the ceiling, a minimum rating of 110 candela is permitted. (3) A visible notification appliance in an area other than a room designed for sleeping must have a minimum rating of 15 candela. (g) Testing and maintenance. (2) Home manufacturers must provide specific written instructions for installers on how to inspect and test the operation of smoke alarms during installation of the home. These instructions must indicate that any smoke alarm that does not meet the inspection or testing requirements needs to be replaced and retested. (3) Home manufacturers must provide the homeowner with the alarm manufacturer's information describing the operation, method and frequency of testing, and proper maintenance of the smoke alarm. This information must be provided in same manner and location as the consumer manual required by § 3282.207 of this chapter, but does not have to be incorporated into the consumer manual. No dealer, distributor, construction contractor, or other person shall interfere with the distribution of this information [67 FR 12817, Mar. 19, 2002, as amended at 67 FR 49795, July 31, 2002. Redesignated at 78 FR 73982, Dec. 9, 2013; 86 FR 2518, Jan. 12, 2021; 89 FR 75745, Sept. 16, 2024] § 3280.210 Fire testing. All fire testing conducted in accordance with this subpart shall be performed by nationally recognized testing laboratories which have expertise in fire technology. In case of dispute, the Secretary shall determine if a particular agency is qualified to perform such fire tests. [49 FR 32011, Aug. 9, 1984. Redesignated at 78 FR 73982, Dec. 9, 2013] § 3280.211 Carbon monoxide alarm requirements. (a) Labeling. (b) Required carbon monoxide alarm locations. (c) Interconnectivity. (d) Connection to power source. (e) Combination alarms. (f) Basement applications. (g) Testing. [86 FR 2519, Jan. 12, 2021, as amended at 89 FR 75745, Sept. 16, 2024] § 3280.212 Factory constructed or site-built attached garages. (a) When a manufactured home is designed for factory construction with an attached garage or is designed for construction of an attached site-built garage that is not self-supported, the manufacturer must design the manufactured home to accommodate all appropriate live and dead loads from the attached garage structure that will be transferred through the manufactured home structure to the home's support and anchoring systems. (b) The design must specify the following home and garage characteristics including maximum width, maximum sidewall height, maximum roof slope, live and dead loads, and other design limitations or restrictions using loads provided by this Code. (c) When a manufactured home is factory constructed with an attached garage or is constructed for the attachment of a site-built garage, provisions must be made to provide fire separation between the garage and the manufactured home. (1) The garage must be separated from the manufactured home and its attic by not less than 1/2 5/8 1/2 (2) [Reserved] (d) Openings from a garage directly into a room designated for sleeping purposes are not permitted. (e) Other openings between the garage and the manufactured home must: (1) Be equipped with solid wood doors not less than 1 3/8 3/8 (2) Be in addition to the two exterior doors required by § 3280.105. (f) Ducts penetrating the walls or ceilings separating the manufactured home from the garage must be constructed of a minimum No. 26 gauge steel or other approved material and must have no openings into the garage. (g) Installation instructions shall be provided by the home manufacturer that, in addition to addressing the fire separation as required in this section, shall identify acceptable attachment locations, indicate design limitations for the attachment of the garage including acceptable live and dead loads for which the home has been designed to accommodate, and provide support and anchorage designs as necessary to transfer all imposed loads to the ground in accordance with §§ 3285.301 and 3285.401 of this chapter. (h) A site-built, self-supported garage is considered an add-on, per 3282.8(j)(1), that does not affect the ability of the manufactured home to comply with the Construction and Safety Standards. The design and construction of the garage is subject to state and or local authorities having jurisdiction. [86 FR 2519, Jan. 12, 2021] § 3280.213 Factory constructed or site-built attached carports. (a) When a manufactured home is designed for factory construction with an attached carport or is designed for construction of an attached site-built carport, the manufacturer must design the manufactured home to accommodate all appropriate live and dead loads from the attached carport structure that will be transferred through the manufactured home structure to the home's support and anchoring systems. (b) The design, including the home's installation instructions, must specify the following home and carport characteristics including maximum width, maximum sidewall height, live and dead loads, and other design limitations or restrictions. (1) Alternatively, the manufacturer may provide, by design and home installation instructions, the maximum live and dead loads, and the applied loading locations, that the home is designed to resist from the carport, and other design limitations or restrictions. (2) [Reserved]. (c) Homes may be designed with a factory-installed host beam ( i.e., i.e., (1) Any portion of the host beam ( i.e., (2) [Reserved]. (d) To ensure that the attachment of the carport does not interfere with roof or attic ventilation, the manufacturer must provide specific instructions to ensure continued compliance with the manufactured home roof or attic ventilation requirements in accordance with § 3280.504(d). (e) Installation instructions shall be provided by the home manufacturer that identify acceptable attachment locations, indicate design limitations for the attachment of the carport including acceptable live and dead loads for which the home has been designed to accommodate, and provide support and anchorage designs as necessary to transfer all imposed loads to the ground in accordance with §§ 3285.301 and 3285.401 of this chapter. (1) The manufacturer must ensure that any anchoring system designs incorporating anchorage to resist combined shear wall and carport uplift loads are evaluated for adequacy to resist the combined loads, taking into consideration the limitations of the ground anchor test and certification. (2) [Reserved]. (f) A site-built, self-supported carport is considered an add-on, as provided by § 3282.8(j)(1), that does not affect the ability of the manufactured home to comply with the standards. The design and construction of the carport is subject to state and or local authorities having jurisdiction. [86 FR 2519, Jan. 12, 2021] § 3280.214 Fire sprinkler system requirements. (a) General. (2) This section applies to both stand-alone and multipurpose fire sprinkler systems that do not include the use of antifreeze. (3) A back-flow preventer is not required to separate a stand-alone sprinkler system from the water distribution system. (b) Design. (c) Sprinkler location. (1) Attics and normally unoccupied concealed spaces; (2) Closets not exceeding 24 square feet in area, with the smallest dimension not greater than three feet and having at least one base layer of minimum 5/16 inch thick gypsum board on wall and ceiling surfaces; (3) Bathrooms not more than 55 square feet in area; (4) Garages, carports, open attached porches and similar structures; and (5) Closets or alcoves containing heat-producing appliance, regardless of size if the closet or alcove complies with § 3280.203(b)(3). (d) Sprinklers. (e) Temperature rating and separation from heat sources. (1) Sprinklers separated from heat sources as required by the sprinkler manufacturer's installation instructions are to a have a temperature rating of no less than 135 °F (57 °C) and not more than 170 °F (77 °C). (2) Sprinklers located within the distance to a heat source as specified in table 7.5.5.3 of NFPA 13D (incorporated by reference, see § 3280.4) are to have an intermediate temperature rating not less than 175 °F (79 °C) and not more than 225 °F (107 °C) when installed in the following locations: (i) Attics; (ii) Concealed spaces located directly beneath a roof; and (iii) Directly under skylights where the sprinkler is exposed to direct sunlight. (f) Freezing areas. (g) Sprinkler area of coverage. (h) Sprinkler installation on systems assembled with solvent cement. (i) Painting, caulking or modifying sprinklers is prohibited. (j) Sprinkler piping support. 5/16 (k) Shutoff valves. (l) Means of drainage. (m) Minimum flow rate. 2 (n) Design flow rate. (1) The design flow rate for a room having only one sprinkler shall be the flow rate required for that sprinkler, as determined by paragraph (m) of this section. (2) The design flow rate for a room having two or more sprinklers shall be determined by identifying the sprinkler in that room with the highest required flow rate, based on paragraph (m) of this section, and multiplying that flow rate by two. (3) Where the sprinkler manufacturer's instructions specify different criteria for ceiling configurations that are not smooth, flat and horizontal, the required design flow rate for the room shall comply with the sprinkler manufacturer's instructions. (4) The design flow rate for the sprinkler system shall be the flow required by the room with the largest flow rate, based on paragraph (n)(1), (2), or (3) of this section. (5) For the purposes of this section, it shall be permissible to reduce the design flow rate for a room by subdividing the space into two or more rooms, where each room is evaluated separately with respect to the required design flow rate. Walls and a ceiling shall bound each room. Openings in walls shall have a lintel (header) not less than 8 inches in depth and each lintel shall form a solid barrier between the ceiling and the top of the opening. (o) Pipe sizing and minimum required supply pressure. 3/4 1/2 (2) Piping shall be sized by determining the Available Pressure to offset friction loss in piping and identifying a piping material, diameter and length in accordance with the following: (i) Minimum supply pressure required. Equation 1 to Paragraph (o)(2)(i): PSUP = PT+PLE+PSP Where: PSUP = Pressure required at the fire sprinkler system supply inlet. ( Note: PT = Pressure loss in the fire sprinkler system piping. PLE = Pressure loss from elevation change. ( Note: PSP = Maximum pressure required by a sprinkler. (ii) [Reserved] (3) Determination of PSUP shall be in accordance with the following procedure: (i) Step 1. Note: (ii) Step 2. Note: (iii) Step 3. (p) Testing. (q) Fire Sprinkler System Certificate. Example 1 to Paragraph ( q Fire Sprinkler System Certificate Note: This label contains important information about the fire sprinkler system installed in this home. Please do not remove, alter, or cover this label. General Information Name of Manufacturer: Manufactured Home Serial Number: The residential fire sprinkler system installed in this dwelling unit is in compliance with 24 CFR part 3280.214 Fire Sprinkler System Requirements. The manufactured home installer must ensure that water supply testing is completed by a fire protection technician, as required below at the home site. Warning: Minimum Water Supply Required Warning: gpm (gallons per minute) at not less than___ psi (pounds per square inch) The water supply shall have the capacity to provide the above required design flow rate for the sprinklers for a period of time as follows: 1. Seven minutes for manufactured homes one story in height and less than 2,000 square feet in area. 2. Ten minutes for manufactured homes two or more stories in height or equal to or greater than 2,000 square feet in area. Where a water supply tank, a well system or a combination thereof is used, any combination of tank storage or well system shall be permitted to meet the capacity requirement. An installer shall ensure that a fire protection technician completes and signs this Fire Sprinkler System Certificate and shall maintain a copy of the test report from the onsite testing in accordance with the home manufacturer's instructions and that the above listed required minimum water supply is available. Company and/or Individual Name of Fire Protection Technician: License/Certification Number of Technician: Address of Technician: Date Water Supply Tested: Warning: (r) Sign or valve tag. Warning, the water supply system supplies fire sprinklers that require specific flows and pressures to fight a fire. Devices that restrict the flow or decrease the pressure or automatically shut off the water to the fire sprinkler system, such as water filtration systems, water softeners and automatic shutoff valves, shall not be added to this system during installation without HUD approval. Later actions that may impact the water supply system should not be completed without first contacting the home manufacturer or a fire protection technician. Please do not remove this sign. (s) Component instructions. (t) Manufacturer's installation instructions for fire sprinkler systems. (1) Specific instructions for the inspection and testing of the fire sprinkler system during the installation of the home. (2) Required statement. [89 FR 75745, Sept. 16, 2024] § 3280.215 Multi-dwelling unit manufactured homes. (a) General. (b) Fire resistance walls. (1) Wall assemblies need not extend through attic spaces where the ceiling is protected by not less than 5/8 (2) The structural framing supporting the ceiling is protected by not less than 1/2 (3) A fire resistance rating of 1/2 (c) Supporting construction. (d) Dwelling unit rated penetrations. (1) Through penetrations. (ii) Through penetrations must be protected by an approved penetration fire stop system installed as tested in accordance with ASTM E814 or UL 1479 (both incorporated by reference, see § 3280.4), with a positive pressure differential of not less than 0.01 inch of water and must have an F (iii) Where the penetrating items are steel, ferrous or copper pipes, tubes, or conduits, the material used to fill the annular space must prevent the passage of flame and hot gasses sufficient to ignite cotton waste where subjected to ASTM E119 or UL 263 (both incorporated by reference, see § 3280.4) time temperature fire conditions under a positive pressure differential of not less than 0.01 inch of water at the location of the through penetration for the time period equivalent to the fire resistance rating of the construction penetrated. (2) Membrane penetrations. (i) By membrane penetrations of fire-resistant-rated walls, ceiling/floors and partitions by steel electrical boxes provided they do not exceed 16 square inches in area and the aggregate area of the openings through the membrane does not exceed 100 square inches in any 100 square feet of wall area. The annular space between the wall membrane and the box must not exceed 1/8 (A) A horizontal distance of not less than 24 inches where the wall or partition is constructed with individual non-communicating stud cavities; or (B) A horizontal distance of not less than the depth of the wall cavity, where the wall cavity is filled with loose-fill insulation; or (C) Solid fire blocking in accordance with § 3280.206; or (D) Protecting both boxes with listed putty pads; or (E) Other listed materials and methods. (ii) By membrane penetrations of listed electrical boxes of any materials provided that the boxes have been tested for use in fire resistance rated assemblies and are installed in accordance with the instructions included with the listing. The annular space between the wall membrane and the box must not exceed 1/8 (A) The horizontal distance specified in the listing of the electrical boxes; or (B) Sold fire blocking in accordance with § 3280.206; or (C) Protecting boxes with listed putty pads; or (D) Other listed materials and methods. (iii) By the annular space created by the penetration of a fire sprinkler provided that it is covered by a metal escutcheon plate. [89 FR 75745, Sept. 16, 2024] § 3280.216 Draftstopping requirements for multi-dwelling unit manufactured homes. (a) When there is usable space both above and below the concealed space of a floor/ceiling assembly in multi-dwelling unit manufactured homes, draftstops must be installed so that the area of the concealed space does not exceed 1,000 square feet. Draftstopping must divide the concealed space into approximately equal areas. Where the assembly is enclosed by a floor membrane above and a ceiling membrane below, draftstopping shall be provided in floor-ceiling assemblies under the following circumstances: (1) Ceiling is suspended under the floor framing; or (2) Floor framing is constructed of truss type open-web or perforated members. (b) Draftstopping materials must not be less than 1/2 3/8 (c) Draftstopping must be installed parallel to the floor framing members. (d) The integrity of all draftstops must be maintained. [89 FR 75745, Sept. 16, 2024] Subpart D—Body and Frame Construction Requirements § 3280.301 Scope. This subpart covers the minimum requirements for materials, products, equipment, and workmanship needed to assure that the manufactured home will provide the following: (a) Structural strength and rigidity; (b) Protection against corrosion, decay, insects, rodents, and other similar destructive forces; (c) Protection against wind hazards; (d) Resistance to the elements; and (e) Durability and economy of maintenance. [78 FR 73982, Dec. 9, 2013] § 3280.302 Definitions. The following definitions are applicable to subpart D only: Anchor assembly Anchoring equipment Anchoring system Diagonal tie Footing: Foundation system Ground anchor Loads: Dead load: (2) Live load: (3) Wind load: Main frame: Pier: Sheathing: Stabilizing devices Support system: Support system Tie: Vertical tie: [58 FR 55005, Oct. 25, 1993; 59 FR 15113, Mar. 31, 1994, as amended at 72 FR 59361, Oct. 19, 2007] § 3280.303 General requirements. (a) Minimum requirements. minimum, not less than, at least, (b) Construction. (c) Structural analysis. (d) [Reserved] (e) New materials and methods. (2) Unless based on accepted engineering design for the use indicated, all new manufactured home materials, equipment, systems or methods of construction not provided for in this standard shall be subjected to the tests specified in paragraph (g) of this section. (f) Allowable design stress. (g) Alternative test procedures. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55005, Oct. 25, 1993; 59 FR 2469, Jan. 14, 1994; 70 FR 72043, Nov. 30, 2005; 89 FR 75748, Sept. 16, 2024] § 3280.304 Materials. (a) Dimension and board lumber must not exceed 19 percent moisture content at the time of installation, except that treated lumber used for exterior purposes only and does not extend into the main home construction may have a moisture content exceeding 19 percent. (b) The standards for some of the generally used materials and methods of construction that are listed in this paragraph (b) are incorporated by reference (see § 3280.4). (1) Aluminum. (ii) Aluminum Design Manual, Specifications and Guidelines for Aluminum Structures, Part 1-B (Aluminum Association). (2) Steel. (ii) North American Specification for the Design of Cold-Formed Steel Structural Members—AISI S100. (iii) Specification for the Design of Cold-Formed Stainless Steel Structural Members—SEI/ASCE 8. (iv) Standard Specifications Load Tables and Weight Tables for Steel Joists and Joist Girders—SJI. (v) Structural Applications of Steel Cables for Buildings—ASCE 19. (vi) Standard Specification for Strapping, Flat Steel and Seals—ASTM D3953. (3) Wood and wood products. (ii) Prefinished Hardboard Paneling—ANSI A135.5 (Composite Panel Association). (iii) Engineered Wood Siding—ANSI A135.6 (Composite Panel Association). (iv) American National Standard for Hardwood and Decorative Plywood—ANSI/HPVA HP-1 (Decorative Hardwoods Association). (v) Structural Design Guide for Hardwood Plywood Wall Panels—HP-SG (Decorative Hardwoods Association). (vi) For Wood Products—Structural Glued Laminated Timber—ANSI/AITC A190.1. (vii) Structural Plywood (With Typical APA Trademarks)—NIST PS 1. (viii) APA Design/Construction Guide, Residential and Commercial Structures—APA E30-P. (ix) National Design Standard for Metal Plate Connected Wood Truss Construction, TPI 1. (x) Design and Fabrication of All-Plywood Beams—H815G. (xi) Panel Design Specification—APA D510C. (xii) Design and Fabrication of Glued Plywood-Lumber Beams—APA S812S. (xiii) Design and Fabrication of Plywood Curved Panels—APA S811P. (xiv) Design and Fabrication of Plywood Sandwich Panels, APA U814J. (xv) Performance Standard for Wood-Based Structural Use Panels—NIST PS 2. (xvi) Design and Fabrication of Plywood Stressed-Skin Panels—APA U813M. (xvii) National Design Specifications for Wood Construction, with Supplement, Design Values for Wood Construction—AWC NDS. (xviii) Wood Structural Design Data (AFPA). (xix) Span Tables for Joists and Rafters: American Softwood Lumber Standard (PS 20-10) Sizes—AWC-2012. (xx) Design Values for Joists and Rafters, Supplement to Span Tables for Joists and Rafters—AWC-2012. (xxi) Particleboard—ANSI A208.1 (Composite Panel Association). (xxii) North American Fenestration Standard/Specification for Windows, Doors and Skylights—AAMA/WDMA/CSA 101/I.S.2/A440 (CSA Group). (xxiii) Standard Test Methods for Puncture and Stiffness of Paperboard, and Corrugated and Solid Fiberboard—ASTM D781. (xxiv) Standard Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials—ASTM D4442. (xxv) Standard Test Method for Laboratory Standardization and Calibration of Hand-Held Moisture Meters—ASTM D4444. (xxvi) Medium Density Fiberboard (MDF) For Interior Applications—ANSI A208.2. (xxvii) Standard Test Methods for Fire Tests of Building Construction and Materials—ASTM E119. (xxviii) Engineered Wood Construction Guide—APA E30V. (xxix) Plywood Design—APA Y510. (4) Other. (ii) [Reserved] (5) Fasteners. (ii) [Reserved] (6) Unclassified. (ii) Safety Glazing Materials Used in Buildings—Safety Performance Specifications and Methods of Test—ANSI Z97.1. (iii) Standard Specification for Rigid Poly (Vinyl Chloride) (PVC) Siding—ASTM D3679-09a. (iv) Standard Practice for Installation of Rigid Poly (Vinyl Chloride) (PVC) Siding and Soffit—ASTM D4756. (v) Standard Specification for Polypropylene (PP) Siding—ASTM D7254. (c) Materials and methods of construction utilized in the design and construction of manufactured homes which are covered by the standards listed in this section, or any applicable portion thereof shall comply with these requirements. (d) Engineering analysis and testing methods contained in these references shall be utilized to judge conformance with accepted engineering practices required in § 3280.303(c). (e) Materials and methods of installation conforming to these standards shall be considered acceptable when installed in conformance with the requirements of this part. (f) Materials meeting the standards listed in this section (or the applicable portion thereof) are considered acceptable unless otherwise specified herein or unless substantial doubt exists as to conformance. (g) Wood products shall be identified as complying with the appropriate standards. [40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55006, Oct. 25, 1993; 59 FR 15113, Mar. 31, 1994; 70 FR 72043, Nov. 30, 2005; 78 FR 73982, Dec. 9, 2013; 89 FR 75748, Sept. 16, 2024] § 3280.305 Structural design requirements. (a) General. 1/8 (b) Design loads Design dead loads. (2) Design live loads. (3) When engineering calculations are performed, allowable unit stresses may be increased as provided in the documents referenced in § 3280.304 except as otherwise indicated in §§ 3280.304(b)(1) and 3280.306(a). (4) Whenever the roof slope does not exceed 20 degrees, the design horizontal wind loads required by § 3280.305(c)(1) may be determined without including the vertical roof projection of the manufactured home. However, regardless of the roof slope of the manufactured home, the vertical roof projection shall be included when determining the wind loading for split level or clerestory-type roof systems. (c) Wind, snow, and roof loads Wind loads—design requirements. Standard wind loads (Zone I (ii) Wind loads for high wind areas (Zone II and Zone III). (A) The design wind loads for Exposure C specified in ANSI/ASCE 7-88, “Minimum Design Loads for Buildings and Other Structures,” for a fifty-year recurrence interval, and a design wind speed of 100 mph, as specified for Wind Zone II, or 110 mph, as specified for Wind Zone III (Basic Wind Zone Map); or (B) The wind pressures specified in the following table: Table of Design Wind Pressures Element Wind zone II design wind speed 100 MPH Wind zone III design wind speed 110 MPH Anchorage for lateral and vertical stability (See § 3280.306(a)): Net Horizontal Drag 1 2 3 3 Uplift 4 5 −32 PSF Main wind force resisting system: Shearwalls, Diaphragms and their Fastening and Anchorage Systems 1 2 ±39 PSF ±47 PSF Ridge beams and other Main Roof Support Beams (Beams supporting expanding room sections, etc.) −30 PSF −36 PSF Components and cladding: Roof trusses 4 5 5 Exterior roof coverings, sheathing and fastenings 4 6 7 5 5 Within 3′-0′ from each gable end (overhang at end wall) of the roof or endwall if no overhang is provided 4 6 7 5 5 Within 3′-0′ from the ridge and eave (overhang at sidewall) or sidewall if no eave is provided 4 6 7 5 5 Eaves (Overhangs at Sidewalls) 4 6 7 5 5 Gables (Overhangs at Endwalls) 4 6 7 5 5 Wall studs in sidewalls and endwalls, exterior windows and sliding glass doors (glazing and framing), exterior coverings, sheathing and fastenings 8 Within 3′-0′ from each corner of the sidewall and endwall ±48 PSF ±58 PSF All other areas ±38 PSF ±46 PSF NOTES: 1 2 3 4 5 6 7 8 (iii) One-piece metal roofing capable of resisting the design wind pressures for “Components and Cladding: (Exterior roof coverings)” in the Table for Design Wind Pressures in this section is allowed to be used without structural sheathing, provided the metal roofing is tested using procedures that have been approved by HUD and that meet all requirements of §§ 3280.303(c) and (g) and 3280.401. (2) Wind loads—zone designations. (i) Wind Zone I. (ii) Wind Zone II. Local governments: Alabama: Florida: Georgia: Louisiana: Maine: Massachusetts: Mississippi: North Carolina: South Carolina: Texas: Virginia: (iii) Wind Zone III. (A) States and Territories: (B) Local governments: Florida: Louisiana: North Carolina: (iv) Consideration of local requirements. (3) Snow and roof loads. Zone (see Map in § 3280.305(c)(4)) Pounds per square foot North Zone 40 Middle Zone 30 South Zone 20 (A) North Roof Load Zone. Maine—Aroostook, Piscataquis, Somerset, Penobscot, Waldo, Knox, Hancock, and Washington. Alaska—All Counties (B) Middle Roof Load Zone. States Counties South Dakota Grant Brookings Hanson Lincoln Codington Miner Minnehaha Yankton Deuel Lake Hutchinson Union Hamlin Moody Turner Clay Kingsbury McCook Minnesota Koochiching Stearns Renville Sibley Itasca Swift McLeod Nicollet Hubbard Kandiyohi Carver Blue Earth Cass Meeker Dakota Martin Crow Wing Wright Goodhue Watonwan Aitkin Lac qui Parle Wabasha Brown St. Louis Chippewa Winona Redwood Lake Yellow Medicine Fillmore Lyon Cook Mille Lacs Mower Lincoln Carlton Kanabec Olmsted Pipestone Pine Benton Dodge Murray Wadena Isanti Rice Cottonwood Todd Sherburne Steele Jackson Morrison Anoka Freeborn Nobles Douglas Chisapo Faribault Rock Grant Washington Waseca Stevens Hennepin Le Sueur Pope Ramsey Scott Iowa Hancock Mitchell Hamilton Buena Vista Lyon Howard Webster Cherokee Osceola Chickasaw Calhoun Plymouth Dickinson Butler Sac Sioux Emmet Floyd Ida O'Brien Kossuth Cerro Gordo Humboldt Clay Winnebago Franklin Pocahontas Wright Worth Hardin Palo Alto Wisconsin Douglas Oconto Pepin Lincoln Bayfield Menominee Pierce Oneida Ashland Langlade Dunn Polk Iron Marathon Eau Claire Burnett Vilas Clark Chippewa Washburn Forest Jackson Rusk Sawyer Florence Trempealeau Barron Price Marinette Buffalo Taylor Door St. Croix Michigan Houghton Iron Presque Isle Wexford Baraga Dickinson Charlevoix Benzie Marquette Menominee Montmorency Grand Traverse Alger Delta Alpena Kalkaska Luce Schoolcraft Alcona Oscoda Chippewa Mackinac Ogemaw Otsego Keweenaw Cheyboygan Roscommon Leelanau Ontonagon Emmet Missaukee Antrim Gogebic Crawford New York St. Lawrence Herkimer Onondaga Genesee Franklin Lewis Madison Orleans Clinton Oswego Cayuga Niagara Essex Jefferson Seneca Erie Hamilton Oneida Wayne Wyoming Warren Fulton Ontario Monroe Saratoga Montgomery Yates Washington Schenectady Livingston Massachusetts Essex Maine Franklin Kennebec Lincoln Cumberland Oxford Androscoggin Sagadahoc York Montana All Counties Idaho All Counties Colorado All Counties Wyoming All Counties Utah All Counties Vermont Franklin Orleans Caledonia Addison Grand Isle Essex Washington Rutland Lamoille Chittenden Orange Windsor New Hampshire All Counties (C) South Roof Load Zone. (ii) Consideration of local requirements. (iii) Eaves and cornices shall be designed for a net uplift pressure of 2.5 times the design uplift wind pressure cited in § 3280.305(c)(1)(i) for Wind Zone I, and for the design pressures cited in § 3280.305(c)(1)(ii) for Wind Zones II and III. (iv) Skylights must be capable of withstanding roof loads as specified in paragraphs (c)(3)(i) or (c)(3)(ii) of this section. Skylights must be listed and tested in accordance with AAMA 1600/I.S.7-00, 2003, Voluntary Specification for Skylights. (4) Data plate requirements. 1/2 1/4 (d) Design load deflection. Floor—L/240 Roof and ceiling—L/180 Headers, beams, and girders (vertical load)—L/180 Walls and partitions—L/180 (2) The allowable eave or cornice deflection for uplift is to be measured at the design uplift load of 9 psf for Wind Zone I, and at the design uplift pressure cited in paragraph (c)(1)(ii) of this section for Wind Zones II and III. The allowable deflection shall be (2 × Lc)/180, where Lc is the measured horizontal eave projection from the wall. (e) Fastening of structural systems. (2) For Wind Zone II and Wind Zone III, roof framing members must be securely fastened at the vertical bearing points to resist design overturning, uplift, and sliding forces. When engineered connectors are not installed, roof framing members must be secured at the vertical bearing points to wall framing members (studs), and wall framing members (studs) must be secured to floor framing members, with 0.016 inch base metal, minimum steel strapping or engineered connectors, or by a combination of 0.016 inch base metal, minimum steel strapping or engineered connectors, and structural-rated wall sheathing that overlaps the roof and floor system if substantiated by structural analysis or by suitable load tests. Steel strapping or engineered connectors are to be installed at a maximum spacing of 24 inches on center in Wind Zone II, and 16 inches on center in Wind Zone III. Exception: (f) Walls. (1) Except where substantiated by engineering analysis or tests, studs shall not be notched or drilled in the middle one-third of their length. (2) Interior walls and partitions shall be constructed with structural capacity adequate for the intended purpose and shall be capable of resisting a horizontal load of not less than five pounds per square foot. An allowable stress increase of 1.33 times the permitted published design values may be used in the design of wood framed interior partitions. Finish of walls and partitions shall be securely fastened to wall framing. (g) Floors. 2 (2) Wood, wood fiber or plywood floors or subfloors in kitchens, bathrooms (including toilet compartments), laundry areas, water heater compartments, and any other areas subject to excessive moisture shall be moisture resistant or shall be made moisture resistant by sealing or by an overlay of nonabsorbent material applied with water-resistant adhesive. Use of one of the following methods would meet this requirement: (i) Sealing the floor with a water-resistant sealer; or (ii) Installing an overlay of a non-absorbent floor covering material applied with water-resistant adhesive; or (iii) Direct application of a water-resistant sealer to the exposed wood floor area when covered with a non-absorbent overlay; or (iv) The use of a non-absorbent floor covering which may be installed without a continuous application of a water-resistant adhesive or sealant when the floor covering meets the following criteria: (A) The covering is a continuous membrane with any seams or patches seam bonded or welded to preserve the continuity of the floor covering; and (B) The floor is protected at all penetrations in these areas by sealing with a compatible water-resistant adhesive or sealant to prevent moisture from migrating under the nonabsorbent floor covering; and (C) The covering is fastened around the perimeter of the subfloor in accordance with the floor covering manufacturer's instructions; and, (D) The covering is designed to be installed to prevent moisture penetration without the use of a water-resistant adhesive or sealer except as required in this paragraph (g). The vertical edges of penetrations for plumbing shall be covered with a moisture-resistant adhesive or sealant. The vertical penetrations located under the bottom plates of perimeter walls of rooms, areas, or compartments are not required to be sealed; this does not include walls or partitions within the rooms or areas. (3) Wood panel products used as floor or subfloor materials on the exterior of the home, such as in recessed entryways, must be rated for exterior exposure and protected from moisture by sealing or applying nonabsorbent overlay with water resistant adhesive. (4) Carpet or carpet pads shall not be installed under concealed spaces subject to excessive moisture, such as plumbing fixture spaces, floor areas under installed laundry equipment. Carpet may be installed in laundry space provided: (i) The appliances are not provided; (ii) The conditions of paragraph (g)(2) of this section are followed; and (iii) Instructions are provided to remove carpet when appliances are installed. (5) Except where substantiated by engineering analysis or tests: (i) Notches on the ends of joists shall not exceed one-fourth the joist depth. (ii) Holes bored in joists shall not be within 2 inches of the top or bottom of the joist, and the diameter of any such hole shall not exceed one-third the depth of the joist. (iii) Notches in the top or bottom of the joists shall not exceed one-sixth the depth and shall not be located in the middle third of the span. (6) Bottom board material (with or without patches) must meet or exceed the level of 48 inch-pounds of puncture resistance as tested by the Beach Puncture Test in accordance with Standard Test Methods for Puncture and Stiffness of Paperboard, and Corrugated and Solid Fiberboard, ASTM D781-1968 (Reapproved 1973) (incorporated by reference, see § 3280.4). The material must be suitable for patches and the patch life must be equivalent to the material life. Patch installation instruction must be included in the manufactured home manufacturer's instructions. The bottom board material must be tight fitted against all penetrations. (h) Roofs. (2) Roofing membranes shall be of sufficient rigidity to prevent deflection which would permit ponding of water or separation of seams due to wind, snow, ice, erection or transportation forces. (3) Cutting of roof framework members for passage of electrical, plumbing or mechanical systems shall not be allowed except where substantiated by engineering analysis. (4) All roof penetrations for electrical, plumbing or mechanical systems shall be properly flashed and sealed. In addition, where a metal roof membrane is penetrated, a wood backer shall be installed. The backer plate shall be not less than 5/16 (5) Portions of roof assemblies, including, but not limited to, dormers, gables, crickets, hinged roof sections, sheathing, roof coverings, underlayments, flashings, and eaves and overhangs are permitted to be assembled and installed on site in accordance with 24 CFR part 3282, subpart M, provided that the requirements in paragraphs (h)(5)(i) through (iv) of this section are met. (i) Approved installation instructions must be provided that include requirements for the following items: (A) Materials, installation, and structural connections complying with this section; (B) Installation and fastening of sheathing and roof coverings; (C) Installation of appliance vent systems in accordance with § 3280.710; (D) Installation of plumbing vents as required by § 3280.611; and (E) Installation of attic ventilation in accordance with § 3280.504(c). (ii) The installation instructions specified in paragraph (h)(5)(i) of this section must include drawings, details, and instructions as necessary to assure that the on-site work complies with the approved design. (iii) The installation instructions specified in paragraph (h)(5)(i) of this section must provide for inspection of the work at the installation site. As necessary to ensure conformance, inspection panels may be required, or inspections may need to occur in stages that assure inspections are performed before any work is concealed. Such inspection procedures shall be addressed in the approved installation instructions. (iv) Temporary weather protection must be provided per § 3280.307(e). (i) Frame construction. (1) [Reserved] (2) Protection of metal frames against corrosion. (j) Welded connections. (2) Regardless of the provisions of any reference standard contained in this subpart, deposits of weld slag or flux shall be required to be removed only from welded joints at the following locations: (i) Drawbar and coupling mechanisms; (ii) Main member splices, and (iii) Spring hanger to main member connections. (k) Attics. (2) For roofs with slopes less than 7:12 that contain an attic area or for portions of roofs with slopes 7:12 or greater that do meet the ceiling height/living space requirements of the standards, the attic floor must be designed for a storage live load of 20 pounds per square foot (psf). (i) Attic area as used within this section are those spaces where the maximum clear height between joist and rafters is 42 inches or greater or where there are two or more adjacent trusses with web configurations capable of accommodating an assumed rectangle 42 inches high by 24 inches in width or greater, within the plane of the trusses. (ii) The live load need only be applied to those portions of the joist or truss bottom chords where all of the following criteria are met: (A) The attic area is accessible from an opening not less than 20 inches in width and 30 inches in length that is located where the clear height in the attic is a minimum of 30 inches; and (B) The slope of the joists of the truss bottom chord are no greater than 2 inches vertical to 12 inches horizontal; and (C) Required insulation depth is less than the joist or truss bottom chord member depth. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 44 FR 66195, Nov. 19, 1979; 52 FR 4582, Feb. 12, 1987; 58 FR 55006, Oct. 25, 1993; 59 FR 2469, Jan. 14, 1994; 59 FR 15113, 15114, Mar. 31, 1994; 62 FR 54547, Oct. 20, 1997; 70 FR 72043, Nov. 30, 2005; 71 FR 19638, Apr. 17, 2006; 78 FR 73983, Dec. 9, 2013; 80 FR 53727, Sept. 8, 2015; 86 FR 2520, Jan. 12, 2021; 86 FR 10457, Feb. 22, 2021; 89 FR 75749, Sept. 16, 2024] § 3280.306 Windstorm protection. (a) Provisions for support and anchoring systems. (1) The provisions of this section shall be followed and the support and anchoring systems shall be designed by a Registered Professional Engineer or Architect. (2) The manufacturer of each manufactured home is required to make provision for the support and anchoring systems but is not required to provide the anchoring equipment or stabilizing devices. When the manufacturer's installation instructions provide for the main frame structure to be used as the points for connection of diagonal ties, no specific connecting devices need be provided on the main frame structure. (b) Contents of instructions. (2) For anchoring systems, the instructions shall indicate: (i) The minimum anchor capacity required; (ii) That anchors should be certified by a professional engineer, architect, or a nationally recognized testing laboratory as to their resistance, based on the maximum angle of diagonal tie and/or vertical tie loading (see paragraph (c)(3) of this section) and angle of anchor installation, and type of soil in which the anchor is to be installed; (iii) That ground anchors are to be embedded below the frost line, unless the foundation system is frost-protected in accordance with §§ 3285.312(b) and 3285.404 of the Model Manufactured Home Installation Standards in this chapter. (iv) That ground anchors must be installed to their full depth, and stabilizer plates must be installed in accordance with the ground anchor listing or certification to provide required resistance to overturning and sliding. (v) That anchoring equipment should be certified by a registered professional engineer or architect to resist these specified forces in accordance with testing procedures in ASTM D3953-97, Standard Specification for Strapping, Flat Steel and Seals (incorporated by reference, see § 3280.4). (c) Design criteria. (1) The minimum number of ties provided per side of each home shall resist design wind loads required in § 3280.305(c)(1). (2) Ties shall be as evenly spaced as practicable along the length of the manufactured home, with not more than two (2) feet open-end spacing on each end. (3) Vertical ties or straps shall be positioned at studs. Where a vertical tie and a diagonal tie are located at the same place, both ties may be connected to a single anchor, provided that the anchor used is capable of carrying both loadings, simultaneously. (4) Add-on sections of expandable manufactured homes shall have provisions for vertical ties at the exposed ends. (d) Requirements for ties. (e) Protection requirements. (f) Anchoring equipment—load resistance. (g) Anchoring equipment—weatherization. (1) Slit or cut edges of zinc-coated steel strapping do not need to be zinc coated. (2) Type 1, Finish B, Grade 1 steel strapping, 1 1/4 [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4583, Feb. 12, 1987; 59 FR 2473, Jan. 14, 1994; 70 FR 72045, Nov. 30, 2005; 72 FR 59362, Oct. 19, 2007; 78 FR 73983, Dec. 9, 2013] § 3280.307 Resistance to elements and use. (a) Exterior coverings shall be of moisture and weather resistive materials attached with corrosion resistant fasteners to resist wind, snow and rain. Metal coverings and exposed metal structural members shall be of corrosion resistant materials or shall be protected to resist corrosion. All joints between portions of the exterior covering shall be designed, and assembled to protect against the infiltration of air and water, except for any designed ventilation of wall or roof cavity. (b) Joints between dissimilar materials and joints between exterior coverings and frames of openings shall be protected with a compatible sealant suitable to resist infiltration of air or water. (c) Where adjoining materials or assemblies of materials are of such nature that separation can occur due to expansion, contraction, wind loads or other loads induced by erection or transportation, sealants shall be of a type that maintains protection against infiltration or penetration by air, moisture or vermin. (d) Exterior surfaces shall be sealed to resist the entrance of rodents. (e) Multi-section and attached manufactured homes (see subpart K of this part) are not required to comply with the factory installation of weather-resistant exterior finishes for those areas left open for field connection of the sections provided the following conditions are satisfied: (1) Temporary weather protection for exposed, unprotected construction is provided in accordance with methods to be included in the approved design. (2) Methods for on-site completion and finishing of these elements are included in the approved design. (3) Complete installation instructions and the required materials for finishing these elements are provided. (f) The exterior wall envelope must be designed and constructed in a manner that prevents the accumulation of water within the wall assembly by providing a Water Resistive Barrier (WRB) behind the exterior cladding and a means of draining water that enters the assembly. [40 FR 58752, Dec. 18, 1975, as amended at 86 FR 2520, Jan. 12, 2021; 89 FR 75749, Sept. 16, 2024] § 3280.308 Formaldehyde emission controls for composite wood products (a) Definitions. (b) Formaldehyde emission levels. (1) For hardwood plywood made with a veneer core or composite core, the maximum level is 0.05 parts per million (ppm) of formaldehyde; (2) For medium density fiberboard, the maximum level is 0.11 ppm of formaldehyde; (3) For thin medium density fiberboard, the maximum level is 0.13 ppm of formaldehyde; and (4) For particleboard, the maximum level is 0.09 ppm of formaldehyde. (c) Product certification and continuing qualification. (d) Panel label. (e) Finished good certification label. (f) Non-complying lots. i.e., (g) Stockpiling. (h) Third party certification. [85 FR 5566, Jan. 31, 2020] § 3280.309 Standard for vinyl siding and polypropylene siding used in manufactured homes. (a) Scope. (b) Standards Vinyl siding. (2) Polypropylene siding. (c) Installation. [89 FR 75749, Sept. 16, 2024] Subpart E—Testing § 3280.401 Structural load tests. Every structural assembly tested shall be capable of meeting the Proof Load Test or the Ultimate Load Test as follows: (a) Proof load tests. 1/4 (b) Ultimate load tests. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55007, Oct. 25, 1993; 70 FR 72045, Nov. 30, 2005] § 3280.402 Test procedures for roof trusses. (a) Roof load tests. (b) General. (l) When trusses are tested singly, trusses shall be positioned in a test fixture, with supports properly located and the roof loads evenly applied. See Figure 3280.402(b)(1). (2) When tested in groups of two or more, the top chords are permitted to be sheathed with nominal 1/4-inch × 12-inch plywood strips. The plywood strips shall be at least long enough to cover the top chords of the trusses at the designated design truss spacing. Adjacent plywood strips shall be separated by at least 1/8-inch. The plywood strips shall be nailed with 4d nails or equivalent staples no closer than 8 inches on center along the top chord. The bottom chords of the adjacent trusses shall be permitted to be one of the following: (i) Unbraced; or (ii) Laterally braced together (not cross-braced) with 1-inch × 2-inch stripping no closer than 24 inches on center, nailed with only one 8d nail at each truss. See Figure 3280.402(b)(2). (c) Measuring and loading methods. (d) Testing procedures. (1) Proof load truss test procedure. (i) Dead load. (ii) Live load. 1/4 1/4 (iii) Initial recovery phase. (iv) Continue to load the truss to: (A) Dead load plus 2.0 times the design live load. Maintain this loading for 6 hours and inspect the truss for failure. Failure is rupture, fracture, or excessive yielding; or (B) Dead load plus 1.75 times the design live load. Maintain this loading for 12 hours and inspect the truss for failure. Failure is rupture, fracture, or excessive yielding. (v) Final recovery phase. (vi) Acceptance criteria. (A) The maximum deflection between no load and dead load must be L/480 or less for simply supported clear spans and Lo/180 or less for eave and cornice projections; and (B) The maximum deflection between dead load and design live load must be L/180 or less for simply supported clear spans and Lo/90 or less for eave and cornice projections; and (C) After the design live load is removed, and with the dead load still applied, the maximum recovery deflection must be L/360 or less for simply supported spans and Lo/180 or less for eave and cornice projections; and (D) The truss must maintain the overload condition for 6 hours without rupture or fracture, or excessive yielding; and (E) After 2.0 times the design live load has been removed, and with the dead load still applied, the maximum recovery deflection must be L/180 or less for simply supported clear spans and Lo/90 or less for eave and cornice projections; and (F) As applicable, each truss design must also meet all requirements for uplift loads required by paragraph (d)(3) of this section. For Wind Zone I uplift load requirements, see paragraph (d)(3)(i) of this section. For Wind Zones II and III uplift load requirements, see paragraph (d)(3)(ii) of this section. (2) Ultimate load truss test procedure. (ii) Dead load. (iii) Live load. 1/4 1/4 (iv) Initial recovery phase. (v) Overload phase. (vi) Final recovery phase. (vii) Acceptance criteria. (A) The maximum deflection between no load and dead load must be L/480 or less for simply supported clear spans and Lo/180 or less for eave and cornice projections; and (B) Dead load to design live load deflections shall be L/180 or less for simply supported clear spans and Lo/90 or less for eave and cornice projections; and (C) After the design live load is removed and with the dead load still applied, the maximum recovery deflection must be L/360 or less for simply supported spans and Lo/180 or less for eave and cornice projections; and (D) The truss shall maintain the overload condition for 5 minutes without rupture, fracture, or excessive yielding; and (E) After 2.5 times the design live load is removed, and with the dead load still applied, the truss must recover to at least L/180 for simply supported clear spans and Lo/90 for eave and cornice within 4 hours after the total live load has been removed; and (F) As applicable, each truss design must also meet all requirements for uplift loads in Wind Zone I or Wind Zone II and III, as required by paragraph (d)(3) of this section. For Wind Zone I uplift load requirements, see paragraph (d)(3)(i) of this section. For Wind Zones II and III uplift load requirements, see paragraph (d)(3)(ii) of this section. (3) Uplift load tests. (i) Wind Zone I uplift load test. (ii) Wind Zones II and III uplift loads test. (iii) Trusses designed for use in Wind Zone I, when tested (see paragraph (d)(3)(i) of this section), must be tested in either the inverted position to 2.5 times the net wind uplift load or in the upright position to 1.75 times the net wind uplift load. Trusses designed for use in Wind Zones II and III (see paragraph (d)(3)(ii) of this section) must be tested to 2.0 times the uplift load minus the dead load in the inverted position and to 1.75 times the uplift load minus the dead load in the upright position. See Figure 3280.402(b)(3). (iv) The following describes how to conduct the uplift test with the truss in the upright position. Similar procedures must be used if conducting the test in the inverted position. (A) Place the truss in the test fixture and position as it is intended to be installed in the manufactured home. See Figure 3280.402(b)(3). (B) Position the load measurement devices to register the wind uplift loads that will be applied to the top chord of the truss. The uplift loads shall be applied through tension devices not wider than one inch and spaced not greater than approximately 12 inches on center and shall be applied as uniform as possible, so as to simulate uniform loading. Gravity and wind uplift load tests may be performed on the same truss in this single setup mode. For the wind uplift test, it is permissible to stabilize the bottom chord of the truss in the test fixture to simulate ceiling materials or purlin supports. Measure and record the initial elevation of the bottom chord of the truss in the test position at the mid-span and quarter points of the truss, and at the free end of an eave or cornice projection greater than 12 inches. Scissors or other unique truss configurations are to be measured at as many additional bottom chord panel points as necessary to obtain an accurate representation of the deflected shape of the truss, so as to be able to locate and record the point(s) of maximum deflection. Eave or cornice projection loads are applied separately for eaves or cornice projections greater than 12 inches. For eave or cornice projections greater than 12 inches, the additional required load must be applied to the eave simultaneously with the main body load. For eave or cornice projections of 12 inches or less, add the additional required load to the main body load and apply it to the entire top chord. (C) Measure and record the deflection 5 minutes after the net uplift load has been applied. Design load deflection shall be L/180 or less for a simply supported clear span and Lo/90 or less for eave or cornice projections. (D) For trusses tested in the upright position, continue to load the truss to 1.75 times the net uplift load in paragraph (d)(3)(i) of this section for Wind Zone I and 1.75 times the uplift load in paragraph (d)(3)(ii) for Wind Zones II and III, and maintain the load for one minute. For trusses tested in the inverted position, continue to load the truss to 2.50 times the net uplift load in paragraph (d)(3)(i) for Wind Zone I and to 2.0 times the uplift load minus the dead load in paragraph (d)(3)(ii) for Wind Zones II and III, and maintain the full load for one minute. Regardless of the test position of the truss, upright or inverted, trusses must maintain the overload for the specified time period without rupture, fracture, or excessive yielding. (e) Follow-up testing. (1) All trusses qualifying under these test procedures must be subject to a quality control and follow-up testing program. (i) Manufacturers of listed or labeled trusses must follow an in-house quality control program with follow-up testing approved by a nationally recognized testing program as specified in paragraph (e)(3) of this section. The in-house quality control program must include, at a minimum, procedures for quality of materials including, but not limited to, grade(s) of materials, allowable splits, knots, and other applicable lumber qualities; workmanship including, but not limited to, plate placement and embedment tolerances; other manufacturing tolerances; description and calibration of test equipment; truss retesting criteria; and procedures in the event of noncomplying results. (ii) Those home manufacturers producing trusses for their own use, and which are not listed or labeled, must have an in-house quality control program (see paragraph (i) of this section) that includes follow-up testing, as specified in this section, and is approved by their Design Approval Primary Inspection Agency (DAPIA). (2) Truss designs that are qualified but not in production are not subject to follow-up testing until produced. When the truss design is brought into production, a follow-up test is to be performed if the truss design has been out of production for more than 6 months. (3) The frequency of truss manufacturer's quality control follow-up testing for trusses must be at least: (i) One test for the first 100 trusses produced, with a subsequent test for every 2,500 trusses for trusses qualified under the proof load truss test procedure or inverted uplift test procedure for trusses used in Wind Zones II and III or once every 6 months, whichever is more frequent, for every truss design produced; or (ii) One test for every 4,000 trusses produced for trusses qualified under the ultimate load truss test procedure or upright uplift test procedure for trusses used in Wind Zones II and III or once every 6 months, whichever is more frequent, for every truss design produced. (4) For follow-up testing only, the full dead load may be applied to the top chord of the truss, when the bottom chord dead load is 5 psf or less. [78 FR 4065, Jan. 18, 2013] § 3280.403 Requirements for windows, sliding glass doors, and skylights. (a) Scope. (b)(1) All primary windows and sliding glass doors must comply with AAMA 1701.2 or AAMA/WDMA/CSA 101/I.S.2/A440 (both incorporated by reference, see § 3280.4), except the exterior and interior pressure tests must be conducted at the minimum design wind loads required for components in § 3280.305(c)(1). (2) All skylights must comply with AAMA/WDMA/CSA 101/I.S.2/A440 (incorporated by reference, see § 3280.4). (2) All skylights must comply with AAMA/WDMA/CSA/101/I.S.2/A440-08: North American Fenestration Standard/Specifications for Windows, Doors and Skylights (incorporated by reference, see § 3280.4). Skylights must withstand the roof loads for the applicable Roof Load Zone specified in § 3280.305(c)(3), and the following wind loads: (i) For Wind Zone I, the wind loads specified in § 3280.305(c)(1)(i); and (ii) For Wind Zones II and III, the wind loads specified for exterior roof coverings, sheathing, and fastenings in § 3280.305(c)(1)(ii). (c) Installation. (d) Glass. (2) Sealed insulating glass, where used, must meet all performance requirements for Class C in accordance with ASTM E 774-97, Standard Specification for the Classification of the Durability of Sealed Insulating Glass Units. The sealing system must be qualified in accordance with ASTM E 773-97, Standard Test Methods for Accelerated Weathering of Sealed Insulating Glass Units. Each glass unit must be permanently identified with the name of the insulating glass manufacturer. (e) Certification. (1) All such windows and doors must show evidence of certification by affixing a quality certification label to the product from an independent product certification body accredited to ISO/IEC 17065 (incorporated by reference, see § 3280.4). (2) In determining certifiability of the products, an independent quality assurance agency must conduct pre-production specimen tests in accordance with AAMA 1702.2 or AAMA/WDMA/CSA 101/I.S.2/A440 (both incorporated by reference, see § 3280.4). Further, such agency must inspect the product manufacturer's facility at least twice per year. (3) All skylights installed in manufactured homes must be certified as complying with AAMA 1701.2 or AAMA/WDMA/CSA 101/I.S.2/A440 (both incorporated by reference, see 3280.4). (f) Protection of primary window and sliding glass door openings in high wind areas. [52 FR 4583, Feb. 12, 1987, as amended at 52 FR 35543, Sept. 22, 1987; 58 FR 55009, Oct. 25, 1993; 59 FR 2474, Jan. 14, 1994; 70 FR 72046, Nov. 30, 2005; 78 FR 73983, Dec. 9, 2013; 89 FR 75750, Sept. 16, 2024] § 3280.404 Standard for egress windows and devices for use in manufactured homes. (a) Scope and purpose. (b) Performance. (1) Loading. (2) Dimensions. 2 (c) Installation. See (2) An operational check of each installed egress window or device must be made at the manufactured home factory. All egress windows and devices must be capable of being opened to the minimum required dimensions by normal operation of the window without binding or requiring the use of tools. Any window or device failing this check must be repaired or replaced. A repaired window must conform to its certification. Any repaired or replaced window or device must pass the operational check. (3) Windows that require the removal of the sash to meet egress size requirements are prohibited. (d) Operating instructions. (e) Certification of egress windows and devices. (2) All such windows and devices must show evidence of certification by affixing a quality certification label to the product from an independent product certification body accredited to ISO/IEC 17065 (incorporated by reference, see § 3280.4). (f) Protection of egress window openings in high wind areas. [52 FR 4583, Feb. 12, 1987, as amended at 59 FR 2474, Jan. 14, 1994; 70 FR 72046, Nov. 30, 2005; 78 FR 73983, Dec. 9, 2013; 89 FR 75750, Sept. 16, 2024] § 3280.405 Standard for swinging exterior passage doors for use in manufactured homes. (a) Introduction. (b) Performance requirements. (c) Materials and methods. (d) Exterior doors. see (e) Certification. (1) All such doors must show evidence of certification by affixing a quality certification label to the product from an independent product certification body accredited to ISO/IEC 17065 (incorporated by reference, see § 3280.4). (2) In determining certifiability of the products, an independent quality assurance agency must conduct a pre-production specimen test in accordance with AAMA 1702.2 or AAMA/WDMA/CSA 101/I.S.2/A440 (both incorporated by reference, see § 3280.4). (f) Protection of exterior doors in high wind areas. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4583, Feb. 12, 1987; 52 FR 35543, Sept. 22, 1987; 58 FR 55009, Oct. 25, 1993; 59 FR 2474, Jan. 14, 1994; 70 FR 72046, Nov. 30, 2005; 89 FR 75750, Sept. 16, 2024] § 3280.406 Air chamber test methods for certification and continuing qualification of formaldehyde emission levels. (a) Definitions. (b) Testing requirements. (c) Samples for testing. [85 FR 5566, Jan. 31, 2020] § 3280.407 Quality control testing, manuals, facilities, and personnel. (a) Definitions. (b) Quality control testing. (c) Quality control manuals, facilities, and personnel. [85 FR 5566, Jan. 31, 2020] Subpart F—Thermal Protection § 3280.501 Scope. This subpart sets forth the requirements for condensation control, air infiltration, thermal insulation and certification for heating and comfort cooling. § 3280.502 Definitions. (a) The following definitions are applicable to subpart F only: (1) Pressure envelope (2) Thermal envelope area § 3280.503 Materials. Materials used for insulation shall be of proven effectiveness and adequate durability to assure that required design conditions concerning thermal transmission are attained. § 3280.504 Condensation control and installation of vapor retarders. (a) Ceiling vapor retarders. o (2) For manufactured homes designed for Uo Value Zone 1, the vapor retarder may be omitted. (3) In multi-story manufactured homes, the ceiling vapor retarder is permitted to be omitted when the story directly above is part of the same manufactured home. (b) Exterior walls. (1) Exterior walls shall have a vapor barrier no greater than 1 perm (dry cup method) installed on the living space side of the wall, or (2) Unventilated wall cavities must have an external covering and/or sheathing that forms the pressure envelope. The covering and/or sheathing must have a combined permeance of not less than 5.0 perms. In the absence of test data, combined permeance is permitted to be computed using the following formula: P total = (1/[(1/P 1 2 1 2 (3) Wall cavities must be constructed so that ventilation is provided to dissipate any condensation occurring in these cavities; or (4) Homes manufactured to be sited in “humid climates” or “fringe climates” as shown on the Humid and Fringe Climate Map in this paragraph are permitted to have a vapor retarder specified in paragraph (b)(1) of this section installed on the exterior side of the wall insulation or be constructed with an external covering and sheathing with a combined permeance of not greater than 1.0 perms, provided the interior finish and interior wall panel materials have a combined permeance of not less than 5.0 perms. The following need not meet the minimum combined permeance rating of not less than 5.0 perms for interior finish or wall panel materials: (i) Kitchen back splash materials, less than 50 square feet in area installed around countertops, sinks, and ranges; (ii) Bathroom tub areas, shower compartments; (iii) Cabinetry and built-in furniture; (iv) Trim materials; (v) Hardboard wall paneling of less than 50 square feet in area under chair rails. (5) The following areas of local governments (counties or similar areas, unless otherwise specified), listed by state are deemed to be within the humid and fringe climate areas shown on the Humid and Fringe Climate Map in paragraph (b)(4) of this section, and the vapor retarder or construction methods specified in paragraph (b)(4) of this section may be applied to homes built to be sited within these jurisdictions: Alabama Baldwin, Barbour, Bullock, Butler, Choctaw, Clarke, Coffee, Conecuh, Covington, Crenshaw, Dale, Escambia, Geneva, Henry, Houston, Lowndes, Marengo, Mobile, Monroe, Montgomery, Pike, Washington, Wilcox. Florida All counties and locations within the State of Florida. Georgia Appling, Atkinson, Bacon, Baker, Ben Hill, Berrien, Brantley, Brooks, Bryan, Calhoun, Camden, Charlton, Chatham, Clay, Clinch, Coffee, Colquitt, Cook, Crisp, Decatur, Dougherty, Early, Echols, Effingham, Evans, Glynn, Wayne, Grady, Irwin, Jeff Davis, Lanier, Lee, Liberty, Long, Lowndes, McIntosh, Miller, Mitchell, Pierce, Quitman, Randolph, Seminole, Tattnall, Terrell, Thomas, Tift, Turner, Ware, Worth. Hawaii All counties and locations within the State of Hawaii. Louisiana All counties and locations within the State of Louisiana. Mississippi Adams, Amite, Claiborne, Clarke, Copiah, Covington, Forrest, Franklin, George, Greene, Hancock, Harrison, Hinds, Issaquena, Jackson, Jasper, Jefferson, Jefferson Davis, Jones, Lamar, Lawrence, Lincoln, Marion, Pearl River, Perry, Pike, Rankin, Simpson, Smith, Stone, Walthall, Warren, Wayne, Wilkinson. North Carolina Brunswick, Carteret, Columbus, New Hanover, Onslow, Pender. South Carolina Jasper, Beaufort, Colleton, Dorchester, Charleston, Berkeley, Georgetown, Horry. Texas Anderson, Angelina, Aransas, Atascosa, Austin, Bastrop, Bee, Bexar, Brazoria, Brazos, Brooks, Burleson, Caldwell, Calhoun, Cameron, Camp, Cass, Chambers, Cherokee, Colorado, Comal, De Witt, Dimmit, Duval, Falls, Fayette, Fort Bend, Franklin, Freestone, Frio, Galveston, Goliad, Gonzales, Gregg, Grimes, Guadalupe, Hardin, Harris, Harrison, Hays, Henderson, Hidalgo, Hopkins, Houston, Jackson, Jasper, Jefferson, Jim Hogg, Jim Wells, Karnes, Kaufman, Kennedy, Kinney, Kleberg, La Salle, Lavaca, Lee, Leon, Liberty, Limestone, Live Oak, Madison, Marion, Matagorda, Maverick, McMullen, Medina, Milam, Montgomery, Morris, Nacogdoches, Navarro, Newton, Nueces, Orange, Panola, Polk, Rains, Refugio, Robertson, Rusk, Sabine, San Augustine, San Jacinto, San Patricio, Shelby, Smith, Starr, Titus, Travis, Trinity, Tyler, Upshur, Uvalde, Val Verde, Van Zandt, Victoria, Walker, Waller, Washington, Webb, Wharton, Willacy, Williamson, Wilson, Wood, Zapata, Zavala. (c) Liquid applied vapor retarders. (d) Attic or roof ventilation. (i) A minimum free ventilation area of not less than 1/300 of the attic or roof cavity floor area. At least 50 percent of the required free ventilation area shall be provided by ventilators located in the upper portion of the space to be ventilated. At least 40 percent shall be provided by eave, soffit or low gable vents. The location and spacing of the vent openings and ventilators shall provide cross-ventilation to the entire attic or roof cavity space. A clear air passage space having a minimum height of 1 inch shall be provided between the top of the insulation and the roof sheathing or roof covering. Baffles or other means shall be provided where needed to insure the 1 inch height of the clear air passage space is maintained. (ii) A mechanical attic or roof ventilation system may be installed instead of providing the free ventilation area when the mechanical system provides a minimum air change rate of 0.02 cubic feet per minute (cfm) per sq. ft. of attic floor area. Intake and exhaust vents shall be located so as to provide air movement throughout space. (2) Single section manufactured homes constructed with metal roofs and having no sheathing or underlayment installed, are not required to be provided with attic or roof cavity ventilation provided that the air leakage paths from the living space to the roof cavity created by electrical outlets, electrical junctions, electrical cable penetrations, plumbing penetrations, flue pipe penetrations and exhaust vent penetrations are sealed. (3) Parallel membrane roof section of a closed cell type construction are not required to be ventilated. (4) The vents provided for ventilating attics and roof cavities shall be designed to resist entry of rain and insects. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55009, Oct. 25, 1993; 70 FR 72046, Nov. 30, 2005; 71 FR 19639, Apr. 17, 2006; 78 FR 73984, Dec. 9, 2013; 86 FR 2521, Jan. 12, 2021; 89 FR 75750, Sept. 16, 2024] § 3280.505 Air infiltration. (a) Envelope air infiltration. (1) Envelope penetrations. (2) Joints between major envelope elements. § 3280.506 Heat loss/heat gain. (a) The manufactured home heat loss/heat gain shall be determined by methods outlined in §§ 3280.508 and 3280.509. The Uo (Coefficient of heat transmission) value zone for which the manufactured home is acceptable and the lowest outdoor temperature to which the installed heating equipment will maintain a temperature of 70 F shall be certified as specified in § 3280.510. The Uo value zone shall be determined from the map in figure 1 to this paragraph (a). Figure 1 to Paragraph (a) (b) The overall coefficient of heat transmission (Uo) of the manufactured home for the respective zones and an indoor design temperature of 70 F, including internal and external ducts, and excluding infiltration, ventilation, and condensation control, shall not exceed the Btu/(hr.) (sq. ft.) (F) of the manufactured home envelope are as tabulated in the table to this paragraph (b): Table 1 to Paragraph (b) Uo value zone Maximum coefficient of heat transmission 1 0.116 Btu/(hr.) (sq. ft.) (F). 2 0.096 Btu/(hr.) (sq. ft.) (F). 3 0.079 Btu/(hr.) (sq. ft.) (F). (c) To assure uniform heat transmission in manufactured homes, cavities in exterior walls, floors, and ceilings must be provided with thermal insulation. For insulation purposes, the fire separation wall between each single family attached manufactured home shall be considered an exterior wall (see subpart K of this part). (d) Manufactured homes designed for Uo Value Zone 3 shall be factory equipped with storm windows or insulating glass. [58 FR 55009, Oct. 25, 1993; 59 FR 15113, Mar. 31, 1994; 86 FR 2521, Jan. 12, 2021] § 3280.507 Comfort heat gain. Information necessary to calculate the home cooling load shall be provided as specified in this part. (a) Transmission heat gains. § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values and data necessary for heat loss and heat gain determinations must be taken from the 1997 ASHRAE Handbook of Fundamentals, Inch-Pound Edition, chapters 22 through 27. The following portions of those chapters are not applicable: 23.1 Steel Frame Construction 23.2 Masonry Construction 23.3 Foundations and Floor Systems 23.15 Pipes 23.17 Tanks, Vessels, and Equipment 23.18 Refrigerated Rooms and Buildings 24.18 Mechanical and Industrial Systems 25.19 Commercial Building Envelope Leakage 27.9 Calculation of Heat Loss from Crawl Spaces (b) The calculation of the manufactured home's transmission heat loss coefficient (Uo) must be in accordance with the fundamental principles of the 1997 ASHRAE Handbook of Fundamentals, Inch-Pound Edition, and, at a minimum, must address all the heat loss or heat gain considerations in a manner consistent with the calculation procedures provided in the document, Overall U-values and Heating/Cooling Loads—Manufactured Homes—February 1992-PNL 8006, HUD User No. 0005945. (c) Areas where the insulation does not fully cover a surface or is compressed shall be accounted for in the U-calculation (see § 3280.506). The effect of framing on the U-value must be included in the Uo calculation. Other low-R-value heat-flow paths (“thermal shorts”) shall be explicitly accounted for in the calculation of the transmission heat loss coefficient if in the aggregate all types of low-R-value paths amount to more than 1% of the total exterior surface area. Areas are considered low-R-value heat-flow paths if: (1) They separate conditioned and unconditioned space; and (2) They are not insulated to a level that is at least one-half the nominal insulation level of the surrounding building component. (d) High efficiency heating and cooling equipment credit. Uo adjusted = Uo standard × [1 + (0.6) (heating efficiency increase factor) + (cooling multiplier) (cooling efficiency increase factor)] where: Uo standard = Maximum Uo for Uo Zone required by § 3280.506(a) Uo adjusted = Maximum Uo standard adjusted for high efficiency HVAC equipment Heating efficiency increase factor = The increase factor in heating equipment efficiency measured by the Annual Fuel Utilization Efficiency (AFUE), or the Heating Seasonal Performance Factor (HSPF) for heat pumps, above that required by NAECA (indicated as “NAECA” in formula). The formula is heating efficiency increase factor = AFUE (HSPF) home − AFUE (or HSPF) NAECA divided by AFUE (HSPF) NAECA. Cooling efficiency increase factor = the increase factor in the cooling equipment efficiency measured by the Seasonal Energy Efficiency Ratio (SEER) above that required by NAECA. The formula being cooling equipment = SEER home—SEER NAECA divided by SEER NAECA. The cooling multiplier for the Uo Zone is from the following table: Uo zone Cooling multiplier (Cm) 1 0.60 (Florida only). 1 0.20 (All other locations). 2 0.07. 3 0.03. (e) U values for any glazing (e.g., windows, skylights, and the glazed portions of any door) must be based on tests using AAMA 1503.1-1988, Voluntary Test Method for Thermal Transmittance and Condensation Resistance of Windows, Doors, and Glazed Wall Sections, or the National Fenestration Rating Council 100, 1997 Edition, Procedure for Determining Fenestration Product U-factors. In the absence of tests, manufacturers are to use the residential window U values contained in Chapter 29, Table 5 of the 1997 ASHRAE Handbook of Fundamentals, Inch-Pound Edition. In the event that the classification of the window type is indeterminate, the manufacturer must use the classification that gives the higher U value. Where a composite of materials from two different product types is used, the product is to be assigned the higher U value. For the purpose of calculating U o (f) Annual energy used based compliance. [58 FR 55011, Oct. 25, 1993, as amended at 70 FR 72047, Nov. 30, 2005] § 3280.509 Criteria in absence of specific data. In the absence of specific data, for purposes of heat-loss/gain calculation, the following criteria shall be used: (a) Infiltration heat loss. Infiltration Heat-Loss = 0.7 (T) (ft. of perimeter), BTU/hr. where: T = 70 minus the heating system capacity certification temperature stipulated in the Heating Certificate, in F. (b) Framing areas. Wall 15 percent of wall area less windows and doors. Floor and Ceiling 10 percent of the area. (c) Insulation compression. Table to Paragraph (c)—Effect of Insulation Compression and Restriction on R Original thickness Non-uniform (a) restriction Uniform (b) Batt Blown 0 20 15 0 1 26 21 1 2 32 25 2 3 36 28 4 4 38 30 5 5 41 32 7 6 43 33 8 7 45 35 10 8 46 36 11 9 48 38 13 10 49 39 14 11 51 40 15 12 52 42 17 13 53 43 18 14 54 44 20 15 55 45 21 16 57 46 22 17 58 47 24 18 59 48 25 19 59 49 26 20 60 50 28 21 61 51 29 22 62 52 30 23 63 52 31 24 64 53 33 25 65 54 34 26 65 55 35 27 66 56 36 28 67 57 37 29 68 57 39 30 68 58 40 31 69 59 41 32 70 60 42 33 70 60 43 34 71 61 44 35 72 62 45 36 72 63 47 37 73 63 48 38 74 64 49 39 74 65 50 40 75 65 51 41 75 66 52 42 76 67 53 43 76 68 54 44 77 68 55 45 78 69 56 46 78 70 57 47 79 70 58 48 79 71 59 49 80 71 60 50 80 72 61 51 81 73 62 52 81 73 63 53 82 74 64 54 82 75 65 55 83 75 65 56 83 76 66 57 84 76 67 58 84 77 68 59 84 78 69 60 85 78 70 61 85 79 71 62 86 79 72 63 86 80 73 64 87 81 74 65 87 81 74 66 88 82 75 67 88 82 76 68 88 83 77 69 89 84 78 70 89 84 78 71 90 85 79 72 90 85 80 73 90 86 81 74 91 86 82 75 91 87 82 76 92 87 83 77 92 88 84 78 92 89 85 79 93 89 85 80 93 90 86 81 93 90 87 82 94 91 88 83 94 91 88 84 95 92 89 85 95 92 90 86 95 93 91 87 96 93 91 88 96 94 92 89 96 94 93 90 97 95 93 91 97 95 94 92 97 96 95 93 98 96 95 94 98 97 96 95 98 97 97 96 99 98 97 97 99 98 98 98 99 99 99 99 100 99 99 100 100 100 100 Note: To use this table, first compute the restricted insulation thickness as a fraction of the uncompressed (full) insulation thickness. Then look up the R R R R (a) Non-uniform restriction is that which occurs between non-parallel planes, such as in the ceiling near the eaves. (b) Uniform compression is compression between parallel planes, such as that which occurs in a wall. (d) Air supply ducts within floor cavity. (e) Air supply ducts within ceiling cavity. (f) The supply duct loss (and/or heat gain where applicable—See § 3280.511) shall be calculated using the actual duct surface area and the actual thickness of insulation between the duct and outside of the manufactured home. If there is an air space of at least 1/2 (g) Return air cavities. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 78 FR 73984, Dec. 9, 2013] § 3280.510 Heat loss certificate. The manufactured home manufacturer must permanently affix the following “Certificate” to an interior surface of each dwelling unit that is readily visible to the occupant. The “Certificate” shall specify the following: (a) Heating zone certification. (b) Outdoor certification temperature. (c) Operating economy certification temperature. HEATING CERTIFICATE Home Manufacturer Plant Location Home Model (Include Uo Value Zone Map) This manufactured home has been thermally insulated to conform with the requirements of the Federal Manufactured Home Construction and Safety Standards for all locations within Uo Value Zone ____. Heating Equipment Manufacturer Heating Equipment Model The above heating equipment has the capacity to maintain an average 70F temperature in this home at outdoor temperatures of [see paragraph (b) of this section] F. To maximize furnace operating economy and to conserve energy, it is recommended that this home be installed where the outdoor winter design temperature (97 1/2%) is not higher than [see paragraph (c) of this section] F degrees Fahrenheit. The above information has been calculated assuming a maximum wind velocity of 15 MPH at standard atmospheric pressure. (d) The following additional statement must be provided on the heating certificate and data plate required by § 3280.5 when the home is built with a vapor retarder of not greater than one perm (dry cup method) on the exterior side of the insulation: “This home is designed and constructed to be sited only in humid or fringe climate regions as shown on the Humid and Fringe Climate Map.” A reproduction of the Humid and Fringe Climate Map in § 3280.504 is to be provided on the heating certificate and data plate. The map must be not less than 3 1/2 1/4 o [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55011, Oct. 25, 1993; 70 FR 72048, Nov. 30, 2005; 89 FR 75750, Sept. 16, 2024] § 3280.511 Comfort cooling certificate and information. (a) The manufactured home manufacturer must permanently affix a “Comfort Cooling Certificate” to an interior surface of each dwelling unit that is readily visible to the occupant. This certificate may be combined with the heating certificate required in § 3280.510. The manufacturer shall comply with one of the following three alternatives in providing the certificate and additional information concerning the cooling of the manufactured home: (1) Alternative I. Air Conditioner Manufacturer Air Conditioner Model Certified Capacity ______ BTU/Hr. in accordance with the appropriate Air Conditioning and Refrigeration Institute Standards The central air conditioning system provided with this home has been sized, assuming an orientation of the front (hitch) end of the home facing ______ and is designed on the basis of a 75 °F indoor temperature and an outdoor temperature of __ °F dry bulb and __ °F wet bulb. Example Alternate I COMFORT COOLING CERTIFICATE Manufactured Home Mfg Plant Location Manufactured Home Model Air Conditioner Manufacturer Certified Capacity ______ BTU/Hr. in accordance with the appropriate Air Conditioning and Refrigeration Institute Standards. The central air conditioning system provided with this home has been sized assuming an orientation of the front (hitch end) of the home facing ______. On this basis, the system is designed to maintain an indoor temperature of 75 °F when outdoor temperatures are __ °F dry bulb and __ °F wet bulb. The temperature to which this home can be cooled will change depending upon the amount of exposure of the windows to the sun's radiant heat. Therefore, the home's heat gains will vary dependent upon its orientation to the sun and any permanent shading provided. Information concerning the calculation of cooling loads at various locations, window exposures and shadings are provided in chapter 22 of the 1989 edition of the ASHRAE Handbook of Fundamentals. (2) Alternative 2. Example Alternate 2 COMFORT COOLING CERTIFICATE Manufactured Home Manufacturer Plant Location Manufactured Home Model This air distribution system of this home is suitable for the installation of central air conditioning. The supply air distribution system installed in this home is sized for Manufactured Home Central Air Conditioning System of up to ______ B.T.U./Hr. rated capacity which are certified in accordance with the appropriate Air Conditioning and Refrigeration Institute Standards. When the air circulators of such air conditioners are rated at 0.3 inch water column static pressure or greater for the cooling air delivered to the manufactured home supply air duct system. Information necessary to calculate cooling loads at various locations and orientations is provided in the special comfort cooling information provided with this manufactured home. (3) Alternative 3. Example Alternate 3 COMFORT COOLING CERTIFICATE Manufactured Home Mfg Plant Location Manufactured Home Model The air distribution system of this home has not been designed in anticipation of its use with a central air conditioning system. (b) For each home designated as suitable for central air conditioning the manufacturer shall provide the maximum central manufactured home air conditioning capacity certified in accordance with the ANSI/AHRI Standard 210/240 with Addenda 1 and 2 (incorporated by reference, see § 3280.4) and in accordance with § 3280.715(a)(3). If the capacity information provided is based on entrances to the air supply duct at other than the furnace plenum, the manufacturer shall indicate the correct supply air entrance and return air exit locations. (c) Comfort cooling information. To determine the required capacity of equipment to cool a home efficiently and economically, a cooling load (heat gain) calculation is required. The cooling load is dependent on the orientation, location and the structure of the home. Central air conditioners operate most efficiently and provide the greatest comfort when their capacity closely approximates the calculated cooling load. Each home's air conditioner should be sized in accordance with chapter 22 of the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Handbook of Fundamentals, 1989 Edition, once the location and orientation are known. Information Provided by the Manufacturer Necessary To Calculate Sensible Heat Gain Walls (without windows and doors) U Ceilings and roofs of light color U Ceilings and roofs of dark color U Floors U Air ducts in floor U Air ducts in ceiling U Air ducts installed outside the home U Information necessary to calculate duct areas. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55012, Oct. 25, 1993; 89 FR 75751, Sept. 16, 2024] Subpart G—Plumbing Systems § 3280.601 Scope. Subpart G of this standard covers the plumbing materials, fixtures, and equipment installed within or on manufactured homes. It is the intent of this subpart to assure water supply, drain, waste and vent systems which permit satisfactory functioning and provide for health and safety under all conditions of normal use. § 3280.602 Definitions. The following definitions are applicable to subpart G only: Accessible, Air gap (water distribution system) Backflow Backflow connection Backflow preventer Branch Common vent Continuous vent Continuous waste Critical level Cross connection Developed length Diameter, Drain Drain connector Drain outlet Drainage system Fixture drain Fixture supply Flood-level Flooded Flush tank Flush valve Flushometer tank: Flushometer valve Grade Horizontal branch Horizontal pipe Indirect waste receptor Individual vent Inlet coupling Main Main drain Main vent Mechanical trap vent device Offset Pitch. Grade. Plumbing appliance: Plumbing appurtenance: Plumbing fixtures Plumbing system Primary vent. main vent. Relief vent Secondary vent Sewage Siphonage (a) Self-siphonage resulting from vacuum in a fixture drain generated solely by the discharge of the fixture served by that drain, or, (b) Induced siphonage resulting from vacuum in the drainage system generated by the discharge of one or more fixtures other than the one under observation. Trap Trap arm Trap seal Vacuum breaker. backflow preventer. Vent cap Vent system Vertical pipe Water closet drain Water connection Water connector Water distribution system Wet vent Wet vented drainage system Whirlpool bathtub [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4584, Feb. 12, 1987; 52 FR 47553, Dec. 15, 1987; 58 FR 55012, Oct. 25, 1993; 78 FR 73984, Dec. 9, 2013' 86 FR 2521, Jan. 12, 2021] § 3280.603 General requirements. (a) Minimum requirements. (1) General. (2) Conservation. (3) Connection to drainage system. (4) Workmanship. (5) Components. (6) Prohibited fittings and practices. (ii) Except as specifically provided elsewhere in this standard, vent pipes shall not be used as waste or drain pipes. (iii) Fittings, connections, devices, or methods of installation that obstruct or retard the flow of sewage, or air in the drainage or venting systems in an amount greater than the normal frictional resistance to flow shall not be used unless their use is acceptable in this standard or their use is accepted as having a desirable and acceptable function of ultimate benefit to the proper and continued functioning of the plumbing system. (iv) Cracks, holes, or other imperfections in materials shall not be concealed by welding, brazing, or soldering or by paint, wax, tar, or other leak-sealing or repairing agents. (v) Piping, fixtures or equipment shall be located so as not to interfere with the normal use or with the normal operation and use of windows, doors or other required facilities. (vi) Galvanized pipe shall not be bent or welded. (7) Alignment of fittings. (b) Protective requirements. (2) Exposed piping. (3) Road damage. (4) Freezing. (i) Written installation instructions for the method(s) required for compliance to this section; (ii) A statement in the installation instructions required by § 3280.306(b), stating that if the heat tape or pipe heating cable is used, it must be listed or certified for its intended purpose. (iii) A receptacle outlet complying with § 3280.806(d)(10). (5) All piping, except the fixture trap, shall be designed to allow drainage. (6) Rodent resistance. (7) Piping and electrical wiring shall not pass through the same holes in walls, floors or roofs. Plastic piping shall not be exposed to heat in excess of manufacturers recommendation or radiation from heat producing appliances. [40 FR 58752, Dec. 18, 1975, as amended at 42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55012, Oct. 25, 1993; 78 FR 73985, Dec. 9, 2013; 89 FR 75751, Sept. 16, 2024] § 3280.604 Materials. (a) Minimum standards. (b) Compliance when there is more than one listed standard. (1) When one of the reference standards requires evaluation of chemical, toxicity or odor properties which are not included in the other standard, then conformance to the applicable requirements of each standard shall be demonstrated; or (2) When a plastic material or component is not covered by the standards in this section, it must be certified as non-toxic in accordance with Drinking water system components-Health effects—ANSI/NSF 61 (incorporated by reference, see § 3280.4). (c) List of standards. (1) Ferrous pipe and fittings. (ii) Malleable Iron Threaded Fittings—ANSI/ASME B16.3. (iii) Material and Property Standard for Special Cast Iron Fittings—IAPMO PS 5. (iv) Welded and Seamless Wrought Steel Pipe—ANSI/ASME B36.10. (v) Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53/A53M. (vi) Pipe Threads, General Purpose (Inch)—ANSI/ASME B1.20.1. (vii) Standard Specification for Cast Iron Soil Pipe and Fittings—ASTM A74. (viii) Standard Specification for Hubless Cast Iron Soil Pipe and Fittings for Sanitary and Storm Drain, Waste, and Vent Piping Applications—CISPI-301. (2) Nonferrous pipe and fittings. (ii) Standard Specification for General Requirements for Wrought Seamless Copper and Copper-Alloy Tube—ASTM B251. (iii) Standard Specification for Seamless Copper Water Tube—ASTM B88. (iv) Standard Specification for Copper Drainage Tube (DWV)—ASTM B306. (v) Wrought-Copper and Copper Alloy Solder-Joint Pressure Fitting—ASME/ANSI B16.22. (vi) Wrought Copper and Wrought Copper Alloy Solder-Joint Drainage Fittings-DWV—ASME/ANSI B16.29. (vii) Cast Copper Alloy Solder-Joint Pressure Fittings—ANSI B16.18. (viii) Cast Copper Alloy Solder-Joint Drainage Fittings-DWV—ASME B16.23. (ix) Cast Copper Alloy Fittings for Flared Copper Tubes—ASME/ANSI B16.26. (x) Standard Specification for Seamless Red Brass Pipe, Standard Sizes—ASTM B43. (xi) Cast Bronze Threaded Fittings, Classes 125 and 250—ANSI/ASME B16.15. (3) Plastic pipe and fittings. (ii) Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Drain, Waste, and Vent Pipe and Fittings—ASTM D2665. (iii) Standard Specification for Drain, Waste, and Vent (DWV) Plastic Fittings Patterns—ASTM D3311. (iv) Standard Specification for Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40, Plastic Drain, Waste, and Vent Pipe with a Cellular Core—ASTM F628. (v) Standard Specification for Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Hot- and Cold-Water Distribution Systems—ASTM D2846. (vi) Standard Specification for Polybutylene (PB) Plastic Hot- and Cold-Water Distribution Systems—ASTM D3309. (vii) Plastic Piping Components and Related Materials—ANSI/NSF 14. (viii) Standard Specification for Crosslinked Polyethylene (PEX) Tubing—ASTM F876. (ix) Standard Specification for Crosslinked Polyethylene (PEX) Plastic Hot- and Cold-Water Distribution Systems—ASTM F877. (4) Miscellaneous. (ii) Backflow Valves—ANSI A112.14.1. (iii) Plumbing Fixture Setting Compound—TTP 1536A. (iv) Material and Property Standard for Cast Brass and Tubing P-Traps—IAPMO PS 2. (v) Relief Valves for Hot Water Supply Systems—ANSI Z21.22. (vi) Standard Specification for Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe and Fittings—ASTM D2235. (vii) Standard Specification for Solvent Cements for Poly (Vinyl Chloride) (PVC) Plastic Piping Systems—ASTM D2564. (viii) Specification for Neoprene Rubber Gaskets for HUB and Spigot Cast Iron Soil Pipe and Fittings—CISPI-HSN. (ix) Plumbing System Components for Manufactured Homes and Recreational Vehicles—ANSI/NSF 24. (x) Material and Property Standard for Diversion Tees and Twin Waste Elbow—IAPMO PS 9. (xi) Material and Property Standard for Flexible Metallic Water Connectors—IAPMO PS 14. (xii) Material and Property Standard for Dishwasher Drain Airgaps—IAPMO PS 23. (xiii) Material and Property Standards for Backflow Prevention Assemblies—IAPMO PS 31. (xiv) Performance Requirements for Air Admittance Valves for Plumbing Drainage Systems, Fixture and Branch Devices—ASSE 1051. (xv) Drinking Water System Components-Health Effects—ANSI/NSF 61. (5) Plumbing fixtures. (ii) Vitreous China Plumbing Fixtures—ANSI/ASME A112.19.2(M). (iii) Enameled Cast Iron Plumbing Fixtures—ANSI/ASME A112.19.1M. (iv) Porcelain Enameled Formed Steel Plumbing Fixtures—ANSI/ASME A112.19.4(M). (v) Plastic Bathtub Units with Addenda Z124.1a and Z124.1b—ANSI Z124.1. (vi) Standard for Porcelain Enameled Formed Steel Plumbing Fixtures—IAPMO TSC 22. (vii) Plastic Shower Receptors and Shower Stalls with Addendum Z124.2a—ANSI Z124.2. (viii) Stainless Steel Plumbing Fixtures (Designed for Residential Use)—ANSI/ASME A112.19.3M. (ix) Material and Property Standard for Drains for Prefabricated and Precast Showers—IAPMO PS 4. (x) Plastic Lavatories with Addendum Z124.3a—ANSI Z124.3. (xi) Standard for Safety Glazing Materials used in Buildings—Safety Performance Specifications and Methods of Test—ANSI Z97.1. (xii) Water Heater Relief Valve Drain Tubes—ASME A112.4.1. (xiii) Flexible Water Connectors—ASME A112.18.6. (xiv) Performance Requirements for Backflow Protection Devices and Systems in Plumbing Fixture Fittings—ASME A112.18.3M. (xv) Non-Vitreous Ceramic Plumbing Fixtures—ASME A112.19.9M. (xvi) Dual Flush Devices for Water Closets—ASME A119.19.10. (xvii) Deck Mounted Bath/Shower Transfer Valves with Integral Backflow Protection—ASME A112.18.7. (xviii) Plastic Fittings for Connecting Water Closets to the Sanitary Drainage System—ASME A112.4.3. (xix) Hydraulic Performance Requirements for Water Closets and Urinals—ASME A112.19.6. (xx) Plumbing Fixture Fittings—ASME/ANSI A112.18.1M. (xxi) Trim for Water Closet, Bowls, Tanks, and Urinals—ANSI A112.19.5. (xxii) Plastic Water Closets, Bowls, and Tanks with Addenda Z124.4a—ANSI Z124.4. (xxiii) Plastic Toilet (Water Closets) Seats—ANSI Z124.5. (xxiv) Prefabricated Plastic Spa Shells—ANSI Z124.7. (xxv) Whirlpool Bathtub Appliances—ASME/ANSI A112.19.7M. (xxvi) Plastic Urinal Fixtures—ANSI Z-124.9. (xxvii) Performance Requirements for Automatic Compensating Values for Individual Shower and Tub/Shower Combinations—ASSE 1016. (xxviii) Performance Requirements for Pressurized Flushing Devices (Flushometers) for Plumbing Fixtures—ASSE 1037. (xxix) Performance Requirements for Water Closet Flush Tank Fill Valves (Ballcocks)—ASSE 1002. (xxx) Performance Requirements for Hand-held Showers—ASSE 1014. (xxxi) Hydrants for Utility and Maintenance Use—ANSI/ASME A112.21.3M. (xxxii) Performance Requirements for Home Laundry Equipment—ASSE 1007. (xxxiii) Performance Requirements for Hot Water Dispensers, Household Storage Type Electrical—ASSE 1023. (xxxiv) Plumbing Requirements for Residential Use (Household) Dishwashers—ASSE 1006. (xxxv) Performance Requirements for Household Food Waste Disposer Units—ASSE 1008. (xxxvi) Performance Requirements for Temperature Activated Mixing Valves for Primary Domestic Use—ASSE 1017. (xxxv) Water Hammer Arresters—ANSI A112.26.1. (xxxvi) Suction Fittings for Use in Swimming Pools, Wading Pools, Spas, Hot Tubs, and Whirlpool Bathtub Appliances—ASME/ANSI A112.19.8M. (xxxvii) Air Gaps in Plumbing Systems—ASME A112.1.2. (xxxviii) Performance Requirements for Diverters for Plumbing Faucets with Hose Spray, Anti-Siphon Type, Residential Applications—ASSE 1025. (xxxix) Performance Requirements for Pipe Applied Atmospheric Type Vacuum Breakers—ASSE 1001. (xl) Performance Requirements for Hose Connection Vacuum Breakers—ASSE 1011. (xli) Performance Requirements for Wall Hydrants, Frost Proof Automatic Draining, Anti-Backflow Types—ANSI/ASSE 1019. (xlii) Performance Requirements for Automatic Compensating Values for Individual Shower and Tub/Shower Combinations—ASSE 1016. (xliii) Performance Requirements for Water Temperature Limiting Devices—ASSE 1070. [58 FR 55013, Oct. 25, 1993, as amended at 70 FR 72048, Nov. 30, 2005; 78 FR 73985, Dec. 9, 2013; 79 FR 31863, June 3, 2014; 89 FR 75751, Sept. 16, 2024] § 3280.605 Joints and connections. (a) Tightness. (b) Assembling of pipe. (c) Threaded joints. (d) Solder joints. (e) Plastic pipe, fittings and joints. (f) Union joints. (g) Flared joints. (h) Cast iron soil pipe joints. (1) Approved or listed hub-less pipe and fittings must be permitted to be joined with listed couplings or adapters, per the manufacturer's recommendations. (2) Hub and plain-end soil pipe may be joined by compression fittings per the manufacturer's recommendation. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 53 FR 23611, June 23, 1988; 78 FR 73985, Dec. 9, 2013] § 3280.606 Traps and cleanouts. (a) Traps Traps required. (2) Combination Fixtures. (3) Prohibited traps. (4) Material and design. (5) Trap seal. (6) Size. 1/4 (7) Location. (8) Length of tailpiece. (9) Installation. Grade of trap arm. 1/4 (ii) Trap arm offset. (iii) Concealed traps. (iv) Removability of traps, etc. (b) Cleanout openings Location of cleanout fittings. (ii) A full size cleanout shall be installed at the upper end of any section of drain piping which does not have the required minimum slope of 1/4 (iii) A cleaning tool shall not be required to pass through more than 360 degrees of fittings, excluding removable “P” traps, to reach any part of the drainage system. Water closets may be removed for drainage system access. (2) Access to cleanouts. (3) Material. (4) Design. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55014, Oct. 25, 1993; 78 FR 73985, Dec. 9, 2013] § 3280.607 Plumbing fixtures. (a) General requirements Quality of fixtures. (2) Strainers. (3) Fixture Connections. (i) 1 1/2 (ii) Not less than 1 1/4 (4) Concealed connections. (5) Directional fitting. (6) Water conservation. (b) Fixtures Spacing. (2) Water closets. (ii) Water closet flushing devices shall be designed to replace the water seal in the bowl after each operation. Flush valves, flushometer valves, flushometer tanks and ballcocks shall operate automatically to shut off at the end of each flush or when the tank is filled to operating capacity. (iii) All water closets must be low consumption (1.6 gallons per flush (gpf)) closets. (iv) Flush tanks shall be fitted with an overflow pipe large enough to prevent flooding at the maximum flow rate of the ball cock. Overflow pipes shall discharge into the toilet, through the tank. (v) Floor Connection. 1/4 (vi) Floor connection. (3) Shower compartment. 1/2 (ii) The joint around the drain connection shall be made watertight by a flange, clamping ring, or other approved listed means. (iii) Shower doors and tub and shower enclosures must be constructed so as to be waterproof and, if glazed, glazing must comply with ANSI Z97.1 (incorporated by reference, see § 3280.4) (iv) Prefabricated plumbing fixtures shall be approved or listed. (v) Thresholds in roll-in-type shower compartments must be 1/2 1/2 (vi) Changes in level of 1/4 1/4 1/2 (vii) Shower and tub-shower combination valves must be balanced pressure, thermostatic, or combination mixing valves that conform to the requirements of ASSE 1016 (incorporated by reference, see § 3280.4). Such valves must be equipped with handle position stops that are adjustable in accordance with the valve manufacturer's instructions and to a maximum setting of 120 °F. Hot water supplied to bathtubs and whirlpool bathtubs are to be limited to a temperature of not greater than 120 °F by a water temperature limiting device that conforms to the requirements of ASSE 1070 (incorporated by reference, see § 3280.4). (4) Dishwashing machines. (ii) Drain from a dishwashing machine shall not be connected to a sink tailpiece, continuous waste line, or trap on the discharge side of a food waste disposal unit. (5) Clothes washing machines. (ii) Standpipes must be either 1 1/2 1/2 1/2 (iii) Clothes washing machine drain shall not be connected to the tailpiece, continuous waste, or trap of any sink or dishwashing machine. (c) Installation Access. (2) Alignment. (3) Brackets. (4) Tub supports. (5) Fixture fittings. (6) Hydromassage bathtub Access panel. (ii) Piping drainage. (iii) Piping. (iv) Electrical. [40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4586, Feb. 12, 1987; 58 FR 55014, Oct. 25, 1993; 70 FR 72049, Nov. 30, 2005; 71 FR 19639, Apr. 17, 2006; 78 FR 73985, Dec. 9, 2013; 79 FR 31863, June 3, 2014; 89 FR 75752, Sept. 16, 2024] § 3280.608 Hangers and supports. (a) Strains and stresses. (b) Piping supports. (c) Hangers and anchors. (2) Piping shall be securely attached to the structure by hangers, clamps, or brackets which provide protection against motion, vibration, road shock, or torque in the chassis. (3) Hangers and straps supporting plastic pipe shall not compress, distort, cut or abrade the piping and shall allow free movement of the pipe. [40 FR 58752, Dec. 18, 1975, as amended at 86 FR 2521, Jan. 12, 2021] § 3280.609 Water distribution systems. (a) Water supply Supply piping. (2) Hot water supply. (b) Water outlets and supply connections Water connection. 3/4 (2) Prohibited connections. (ii) No part of the water system shall be connected to any drainage or vent piping. (3) Rim outlets. (4) Appliance connections. (5) Flushometer valves or manually operated flush valves. (6) Flush tanks. (7) Hose bibbs. (8) Flushometer tanks. (c) Water heater safety devices Relief valves. (ii) Any temperature relief valve or combined pressure and temperature relief valve installed for this purpose shall have the temperature sensing element immersed in the hottest water within the upper 6 inches of the tank. It shall be set to start relieving at a pressure of 150 psi or the rated working pressure of the tank whichever is lower and at or below a water temperature of 210 °F. (iii) Relief valves must be provided with full-sized drains, with cross sectional areas equivalent to that of the relief valve outlet. The outlet of a pressure relief valve, temperature relief valve, or combination thereof, must not be directly connected to the drainage system. The discharge from the relief valve must be piped full size separately to the exterior of the manufactured home, not underneath the home, or to an indirect waste receptor located inside the manufactured home. Exterior relief drains shall be directed down and shall terminate between 6″ and 24″ above finished grade. Drain lines must be of a material listed for hot water distribution and must drain fully by gravity, must not be trapped, and must not have their outlets threaded, and the end of the drain must be visible for inspection. (iv) Relief valve piping designed to be located underneath the manufactured home is not required to be installed at the factory provided the manufacturer designs the system for site assembly and also provides all materials and components including piping, fittings, cement, supports, and instructions for proper site installation. (d) Materials Piping material. (i) Plastic piping. (ii) [Reserved] (2) Fittings. (i) Fittings for screw piping shall be standard weight galvanized iron for galvanized iron and steel pipe, and of brass for brass piping. They shall be installed where required for change in direction, reduction of size, or where pipes are joined together. (ii) Fittings for copper tubing shall be cast brass or drawn copper (sweat-soldered) or shall be approved or listed fittings for the purpose intended. (3) Prohibited material. (e) Installation of piping Minimum requirement. (2) Screw pipe. (3) Solder fittings. (4) Flared fittings. (5) Plastic pipe and fittings. (f) Size of water supply piping Minimum size. Minimum Size Tubing and Pipe for Water Distribution Systems Number of fixtures Tubing (nominal) Pipe iron pipe size (inches) Diameter (inches) Outer diameter (inches) 1 * 1 4 3 8 1 2 2 3 8 1 2 1 2 3 1 2 5 8 1 2 4 1 2 5 8 1 2 5 or more 3 4 7 8 3 4 *6 ft maximum length. Exceptions to table: 3/8 1/2 1/2 5/8 1/2 (2) Sizing procedure. (i) Size of branch. (ii) A water heater, food waste disposal unit, evaporative cooler or ice maker shall not be counted as a water-using fixture when computing pipe sizes. (g) Line valves. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4586, Feb. 12, 1987; 53 FR 23611, June 23, 1988; 58 FR 55014, Oct. 25, 1993; 78 FR 73986, Dec. 9, 2013; 86 FR 2521, Jan. 12, 2021; 89 FR 75753, Sept. 16, 2024] § 3280.610 Drainage systems. (a) General. (2) The drainage system shall be designed to provide an adequate circulation of air in all piping with no danger of siphonage, aspiration, or forcing of trap seals under conditions of ordinary use. (b) Materials Pipe. (2) Fittings. 1/4 (i) Fittings for screw pipe shall be cast iron, malleable iron, brass, or listed plastic with standard pipe threads. (ii) Fittings for copper tubing shall be cast brass or wrought copper. (iii) Socket-type fittings for plastic piping shall comply with listed standards. (iv) Brass or bronze adaptor or wrought copper fittings shall be used to join copper tubing to threaded pipe. (c) Drain outlets. General. (2) Clearance from drain outlet. (3) Drain connector. (4) Size Requirement. (5) Preassembly of drain lines. (d) Fixture connections. (1) Water closet connection. (2) [Reserved] (e) Size of drainage piping. (1) Fixture drains serving a single lavatory must be a minimum of 1 1/4 (2) Fixture drains serving two or three fixtures must be a minimum of 1 1/2 (3) Fixture drains serving four or more fixtures that are individually vented must be a minimum of 2 inches in diameter. (4) Fixture drains for water closets must be a minimum of 3 inches in diameter. (f) Wet-vented drainage system. (1) Horizontal piping. 1/2 (2) Size. (3) Length of trap arm. (g) Offsets and branch fittings Changes in direction. 1/4 1/2 (2) Horizontal to vertical. (3) Horizontal to horizontal and vertical to horizontal. (h) Grade of horizontal drainage piping. 1/4 1/4 1/8 [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4586, Feb. 12, 1987; 58 FR 55015, Oct. 25, 1993; 78 FR 73986, Dec. 9, 2013; 86 FR 2521, Jan. 12, 2021] § 3280.611 Vents and venting. (a) General. (b) Materials Pipe. (2) Fittings. (i) Fittings for screw pipe shall be cast iron, malleable iron, plastic, or brass, with standard pipe threads. (ii) Fittings for copper tubing shall be cast brass or wrought copper. (iii) Fittings for plastic piping shall be made to approved applicable standards. (iv) Brass adaptor fittings or wrought copper shall be used to join copper tubing to threaded pipe. (v) Listed rectangular tubing may be used for vent piping only providing it has an open cross section at least equal to the circular vent pipe required. Listed transition fittings shall be used. (c) Size of vent piping Main vent. 1/2 1/2 (i) A 1 1/2 (ii) A 1 1/2 (iii) Two or more vented drains when at least one is wet-vented, or 2-inch diameter (minimum), and each drain is separately connected to the toilet drain. At least one of the drains shall connect within the distance allowed in § 3280.611(c)(5) for 3-inch trap arms. (2) Vent pipe areas. 1/2 1/4 1/2 (3) Common vent. (4) Intersecting vents. (5) The distance of the fixture trap from the vent must not exceed the values given in the following table: Table 1 to Paragraph (c)(5) Size of fixture drain Distance trap to vent 1 1 4 5 ft. 1 1 2 6 ft. 2 8 ft. 3 12 ft. (d) Mechanical Vents. (1) Spring-operated mechanical (anti-siphon) vents must comply with the following: (i) No more than two fixtures individually protected by the spring-operated mechanical vent may be drained by a common 1 1/2 (ii) The drain size for three or more fixtures individually protected by a spring-operated mechanical vent must be at least 2 inches in diameter. (iii) Spring-operated mechanical vents are restricted to venting fixtures with 1 1/2 (iv) A spring-operated mechanical vent must be installed in a location that allows a free flow of air and is accessible for inspection, maintenance, and replacement. The sealing function must be at least 6 inches above the top of the trap arm. (v) Materials for the spring-operated mechanical vents must be as follows: (A) Cap and housing must be listed acrylonitrile-butadiene-styrene, DWV grade; (B) Stem must be DWV grade nylon or acetal; (C) Spring must be stainless steel wire, Type 302; and (D) Sealing disc must be either: ( 1 ( 2 (2) Gravity-operated mechanical (air admittance valves) vents must comply with the following: (i) Where installed to vent any fixture, the drain system must have a minimum 1 1/2 (ii) Where gravity-operated mechanical vent devices terminate in the attic cavity, the following requirements must be met: (A) The attic cavity must be accessible; (B) The sealing device must be installed a minimum of 6 inches above the insulation materials; and (C) The attic must be vented in accordance with § 3280.504(c)(1)(i); (3) Mechanical vents must be installed in accordance with the vent manufacturer's instructions. (e) Grade and connections Horizontal vents. (f) Vent terminal. (1) Roof extension. (2) Wall extensions. (i) Extensions must not be located beneath a door, window, or other opening; (ii) Extensions must be a minimum of 10 feet above the finished floor; (iii) Extensions must be located a minimum of 2 feet above any building opening that is within 10 feet horizontally of any extension; and (iv) Extensions must not terminate under an overhang with soffit vents. (3) Flashing. (g) Vent caps. [40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55015, Oct. 25, 1993; 78 FR 73986, Dec. 9, 2013; 86 FR 2521, Jan. 12, 2021; 89 FR 75753, Sept. 16, 2024] § 3280.612 Tests and inspection. (a) Water system. (b) Drainage and vent system and plumbing fixtures. (1) Water test. (2) Air test. (3) Flood level test. (c) Fixture test. (d) Shower compartments. [40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977; 42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55015, Oct. 25, 1993; 86 FR 2521, Jan. 12, 2021] Subpart H—Heating, Cooling and Fuel Burning Systems § 3280.701 Scope. Subpart H of this standard covers the heating, cooling and fuel burning equipment installed within, on, or external to a manufactured home. § 3280.702 Definitions. The definitions in this subpart apply to subpart H only. Accessible, Air conditioner blower coil system Air conditioner split system Air conditioning condenser section Air conditioning evaporator section Air conditioning self contained system Air duct Automatic pump (oil lifter) Btu. British thermal units Btuh Burner Central air conditioning system Class 0 air ducts and air connectors Class 1 air ducts and air connectors Clearance Combination space heating and water heating appliance Connector-Gas appliance: Direct-vent system Direct-vent system appliance External combination heating/cooling system Factory-built fireplace Fireplace stove Fuel gas piping system Fuel oil piping system Gas clothes dryer Gas refrigerator Gas supply connection Gas supply connector, manufactured home Gas vents (1) Type B gas vent (2) Type BW gas vent Heat producing appliance Heating appliance Liquefied petroleum gases. Liquefied petroleum gases, LPG LP-Gas Plenum (1) Furnace supply plenum is a plenum attached directly to, or an integral part of, the air supply outlet of the furnace. (2) Furnace return plenum is a plenum attached directly to, or an integral part of, the return inlet of the furnace. Quick-disconnect device Readily accessible Roof jack Sealed combustion system appliance Water heater [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4586, Feb. 12, 1987; 58 FR 55015, Oct. 25, 1993; 78 FR 73987, Dec. 9, 2013; 89 FR 75753, Sept. 16, 2024] § 3280.703 Minimum standards. Heating, cooling, and fuel burning appliances and systems in manufactured homes shall be free of defects and shall conform to applicable standards (incorporated by reference, see § 3280.4) in this section unless otherwise specified in this part. When more than one standard is referenced, compliance with any one such standard shall meet the requirements of this part. (a) Appliances. (2) Fixed and Location-Dedicated Electric Room Heaters—UL 2021. (3) Electric Baseboard Heating Equipment—UL 1042. (4) Electric Central Air Heating Equipment—UL 1096. (5) Gas-Burning Heating Appliances for Manufactured Homes and Recreational Vehicles—UL 307B. (6) Gas Clothes Dryers Volume I, Type 1 Clothes Dryers—ANSI Z21.5.1 (CSA Group). (7) Gas-fired Water Heaters, Volume III, Storage Water Heaters with Input Ratings Above 75,000 BTU per Hour, Circulating and Instantaneous—ANSI Z21.10.3 (CSA Group). (8) Gas-Fired, Heat Activated Air Conditioning and Heat Pump Appliances—ANSI Z21.40.1 (CSA Group). (9) Gas-Fired Central Furnaces (Except Direct Vent Systems)—ANSI Z21.47(CSA Group). (10) Connectors for Outdoor Gas Appliances and Manufactured Homes—ANSI Z21.75 (CSA Group). (11) Decorative Gas Appliances for Installation in Solid Fuel Burning Fireplaces—RADCO DS-010. (12) Household Cooking Gas Appliances—ANSI Z21.1 (CSA Group). (13) Refrigerators Using Gas Fuel—ANSI Z21.19 (CSA Group). (14) Gas Water Heaters, Volume I, Storage Water Heaters with Input Ratings of 75,000 BTU per hour or Less—ANSI Z21.10.1 (CSA Group). (15) Household Electric Storage Tank Water Heaters—UL 174. (16) Household and Similar Electrical Appliances—Part 2-40: Particular Requirements for Electrical Heat Pumps, Air-Conditioners and Dehumidifiers—UL 60335-2-40. (17) Smoke Detectors for Fire Protective Signaling Systems—UL 268. (18) Single and Multiple Station Carbon Monoxide Alarms—UL 2034. (19) Electric Heating Appliances—UL 499. (b) Ferrous pipe and fittings. (2) Standard Specification for Electric-Resistance-Welded Coiled Steel Tubing for Gas and Fuel Oil Lines—ASTM A539. (3) Pipe Threads, General Purpose (Inch)—ANSI/ASME B1.20.1. (4) Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10. (c) Nonferrous pipe, tubing, and fittings. (2) Standard Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service—ASTM B280. (3) Connectors for Gas Appliances—ANSI Z21.24 (CSA Group). (4) Manually Operated Gas Valves for Appliances, Appliance Connector Valves and Hose End Valves—ANSI Z21.15 (CSA Group). (5) Standard for Gas Supply Connectors for Manufactured Homes—IAPMO TS 9. (6) Standard Specification for General Requirements for Wrought Seamless Copper and Copper-Alloy Tube—ASTM B251. (7) Standard Specification for Seamless Copper Pipe, Standard Sizes—ASTM B42. (d) Miscellaneous. (2) Closure Systems for use with Rigid Air Ducts and Air Connectors—UL 181A. (3) Closure Systems for use with Flexible Air Ducts and Air Connectors—UL 181B. (4) Safety Glazing Materials Used in Buildings—Safety Performance Specifications and Methods of Test—ANSI Z97.1. (5) Tube Fittings for Flammable and Combustible Fluids, Refrigeration Service, and Marine Use—UL 109. (6) Pigtails and Flexible Hose Connectors for LP-Gas—UL 569. (7) Roof Jacks for Manufactured Homes and Recreational Vehicles—UL 311. (8) Relief Valves for Hot Water Supply Systems—ANSI Z21.22. (9) Automatic electrical controls for household and similar use—Part 2-5: Particular requirements for automatic electrical burner control systems—ANSI Z21.20 (CSA Group). (10) Automatic Valves for Gas Appliances—ANSI Z21.21 (CSA Group). (11) Gas Appliance Thermostats—ANSI Z21.23 (CSA Group). (12) Gas Vents—UL 441. (13) Installation of Oil-Burning Equipment—NFPA 31. (14) National Fuel Gas Code—NFPA 54/ANSI Z223.1. (15) Warm Air Heating and Air Conditioning Systems—NFPA 90B. (16) Liquefied Petroleum Gases Code—NFPA 58. (17) Flares for Tubing—SAE J533. (18) Factory Built Chimneys for Residential Type and Building Heating Appliances—UL 103. (19) Factory-Built Fireplaces—UL 127. (20) Solid-Fuel Type Room Heaters—UL 1482. (21) Fireplace Stoves—UL 737. (22) Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment—ANSI/AHRI Standard 210/240 with Addenda 1 and 2. (23) Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings—ANSI/ASHRAE 62.2. (24) Requirements for Gas Connectors for Connection of Fixed Appliances for Outdoor Installation, Park Trailers, and Manufactured (Mobile) Homes to the Gas Supply—AGA No. 3. [58 FR 55015, Oct. 25, 1993, as amended at 70 FR 72046, Nov. 30, 2005; 78 FR 73987, Dec. 9, 2013; 89 FR 75753, Sept. 16, 2024] § 3280.704 [Reserved] § 3280.705 Gas piping systems. (a) General. 1/2 1/4 (b) Materials. (1) Steel or wrought-iron pipe shall comply with ASME B36.10 (incorporated by reference, see § 3280.4). Threaded brass pipe in iron pipe sizes may be used. Threaded brass pipe shall comply with ASTM B43. (incorporated by reference, see § 3280.4). (2) Fittings for gas piping shall be wrought iron, malleable iron, steel, or brass (containing not more than 75 percent copper). (3) Copper tubing must be annealed type, Grade K or L, conforming to ASTM B88 (incorporated by reference, see § 3280.4), or must comply with the ASTM B280 (incorporated by reference, see § 3280.4). Copper tubing must be internally tinned. (4) Steel tubing must have a minimum wall thickness of 0.032 inch for tubing of 1/2 1/2 (5) Corrugated stainless steel tubing (CSST) systems must be listed and installed in accordance with ANSI LC 1 (CSA Group; incorporated by reference, see § 3280.4), and the requirements of this section. (c) Piping design. (1) All points of crossover beneath the transportable sections must be readily accessible from the exterior of the home. In multi-story manufactured homes, the interconnections between stories must be accessible through a panel on the exterior or interior of the manufactured home. (2) The connection(s) between units must be made with a connector(s) listed for exterior use or direct plumbing sized in accordance with paragraph (d) of this section. A shutoff valve of the non-displaceable rotor type conforming to ANSI Z21.15 (CSA Group; incorporated by reference, see § 3280.4), suitable for outdoor use must be installed at each crossover point upstream of the connection. (3) The connection(s) may be made by a listed quick disconnect device which shall be designed to provide a positive seal of the supply side of the gas system when such device is separated. (4) The flexible connector, direct plumbing pipe, or “quick disconnect” device shall be provided with protection from mechanical and impact damage and located to minimize the possibility of tampering. (5) For gas line cross over connections made with either hard pipe or flexible connectors, the crossover point(s) shall be capped on the supply side to provide a positive seal and covered on the other side with a suitable protective covering. (6) Suitable protective coverings for the connection device(s) when separated, shall be permanently attached to the device or flexible connector. (7) When a quick disconnect device is installed, a 3 inch by 1 3/4 1/4 Do Not Use Tools To Separate the “Quick-Disconnect” Device (d) Gas pipe sizing. 3/4 Table to paragraph ( d 1 2 ID (in.) 10 ft 20 ft 30 ft 40 ft 50 ft 60 ft 70 ft 80 ft 90 ft 100 ft Iron Pipe Sizes—Length 1 4 43 29 24 20 18 16 15 14 13 12 3 8 95 65 52 45 40 36 33 31 29 27 1 2 175 120 97 82 73 66 61 57 53 50 3 4 360 250 200 170 151 138 125 118 110 103 1 680 465 375 320 285 260 240 220 215 195 EHD 2 ID (in.) 10 ft 20 ft 30 ft 40 ft 50 ft 60 ft 70 ft 80 ft 90 ft 100 ft Corrugated Stainless Steel Tubing—Length 1 13 3 8 31 21 17 14 13 12 11 10 10 9 15 3 8 42 30 24 20 18 16 15 14 13 12 18 1 2 79 56 45 39 36 33 30 28 27 25 19 1 2 91 64 52 45 40 36 35 32 31 29 23 3 4 155 111 92 80 72 65 60 58 55 52 25 3 4 184 132 108 93 84 77 71 66 62 60 30 1 317 222 180 156 138 126 116 108 103 97 31 1 368 258 209 180 161 147 135 127 120 113 37 1 1 4 598 426 350 304 273 250 231 217 205 195 OD (in.) 10 ft 20 ft 30 ft 40 ft 50 ft 60 ft 70 ft 80 ft 90 ft 100 ft Copper Tubing—Length 1 4 27 18 15 13 11 10 9 9 8 8 3 8 56 38 31 26 23 21 19 18 17 16 1 2 113 78 62 53 47 43 39 37 34 33 3 4 197 136 109 93 83 75 69 64 60 57 1 280 193 155 132 117 106 98 91 85 81 1 L n, L n 2 (e) Joints for gas pipe. (f) Joints for tubing. (2) Steel tubing joints shall be made with a double-flare in accordance with SAE J533 (incorporated by reference, see § 3280.4). (g) Pipe joint compound. (h) Concealed tubing. (i) The CSST is protected from accidental puncture by a steel strike barrier not less than 0.058 inch thick, or the barrier's equivalent, installed between the tubing and the finished wall and extending 4 inches beyond concealed penetrations of plates, firestops, and wall studs, or specified by the tubing manufacturer's instructions; and (ii) The CSST is installed in single runs and is not rigidly secured. (2) Where tubing passes through exterior walls, floors, partitions, or similar construction, the tubing must be protected by the use of weather-resistant grommets that snugly fit both the tubing and the hole through which the tubing passes, or protected as specified in the tubing manufacturer's instructions. (3) Concealed joints: Piping or tubing joints must not be located in any wall, floor, partition, or similar concealed construction space. (i) Concealed joints. (j) Gas supply connection. (k) Identification of gas supply connections. 3/4 e.g., (l) LP-gas supply connectors General. (2) Appliance connections. (i) No portion of the completed installation shall project beyond the wall of the manufactured home. (ii) The outlet must be provided with an approved quick-disconnect device, which must be designed to provide a positive seal on the supply side of the gas system when the appliance is disconnected. A shutoff valve of the non-displaceable rotor type conforming to ANSI Z21.15 (CSA Group; incorporated by reference, see § 3280.4), must be installed immediately upstream of the quick-disconnect device. The complete device must be provided as part of the original installation. (iii) Protective caps or plugs for the “quick-disconnect” device, when disconnected, shall be permanently attached to the manufactured home adjacent to the device. (iv) A tag shall be permanently attached to the outside of the exterior wall of the manufactured home as close as possible to the gas supply connection. The tag shall indicate the type of gas and the Btuh capacity of the outlet and shall be legibly inscribed as follows: THIS OUTLET IS DESIGNED FOR USE WITH GAS PORTABLE APPLIANCES WHOSE TOTAL INPUT DO NOT EXCEED ______ BTUH. REPLACE PROTECTIVE COVERING OVER CONNECTOR WHEN NOT IN USE. (3) Valves. (4) Gas piping system openings. (5) Electrical ground. (6) Couplings. (7) Hangers and supports. (8) Testing for leakage. (ii) After appliances are connected, the piping system shall be pressurized to not less than 10 inches nor more than 14 inches water column and the appliance connections tested for leakage with soapy water or bubble solution. (iii) Where gas piping between transportable sections must be made on site, the installation instructions must contain provisions for onsite testing for leakage consistent with the provisions in paragraph (l)(8)(i) of this section. [40 FR 58752, Dec. 18, 1975, as amended at 42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4587, Feb. 12, 1987; 58 FR 55016, Oct. 25, 1993; 70 FR 72050, Nov. 30, 2005; 78 FR 73987, Dec. 9, 2013; 86 FR 2522, Jan. 12, 2021; 89 FR 75754, Sept. 16, 2024] § 3280.706 Oil piping systems. (a) General. (b) Materials. (1) Steel or wrought-iron pipe shall comply with ANSI/ASME B36.10 (incorporated by reference, see § 3280.4). Threaded copper or brass paper in iron pipe sizes may be used. (2) Fittings for oil piping shall be wrought-iron, malleable iron, steel, or brass (containing not more than 75 percent copper). (3) Copper tubing must be annealed type, Grade K or L conforming to ASTM B88 (incorporated by reference, see § 3280.4), or shall comply with ASTM B280 (incorporated by reference, see § 3280.4). (4) Steel tubing shall have a minimum wall thickness of 0.032 inch for diameters up to 1/2 1/2 (c) Size of oil piping. 3/8 1/4 (d) Joints for oil piping. (e) Joints for tubing. (f) Pipe joint compound. (g) Couplings. (h) Grade of piping. (i) Strap hangers. (j) Testing Tag. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4588, Feb. 12, 1987; 58 FR 55017, Oct. 25, 1993; 70 FR 72050, Nov. 30, 2005; 78 FR 73988, Dec. 9, 2013; 89 FR 75754, Sept. 16, 2024] § 3280.707 Heat producing appliances. (a) Heat producing appliances and vents, roof jacks and chimneys necessary for their installation in manufactured homes must be listed or certified for residential use by a nationally recognized testing agency. (1) A manufactured home shall be provided with a comfort heating system. (i) When a manufactured home is manufactured to contain a heating appliance, the heating appliance shall be installed by the manufacturer of the manufactured home in compliance with applicable sections of this subpart. (ii) When a manufactured home is manufactured for field application of an external heating or combination heating/cooling appliance, preparation of the manufactured home for this external application shall comply with the applicable sections of this part. (2) Each gas and oil burning comfort heating appliance must have an Annual Fuel Utilization Efficiency of not less than that specified in 10 CFR part 430, Energy Conservation Program for Consumer Products: Test Procedures for Furnaces/Boilers, Vented Home Heating Equipment and Pool Heaters. (b) Fuel-burning heat-producing appliances and refrigeration appliances, except ranges and ovens, shall be of the vented type and vented to the outside. (c) Fuel-burning appliances shall not be converted from one fuel to another fuel unless converted in accordance with the terms of their listing and the appliance manufacturer's instructions. (d) Performance efficiency. (1) All automatic electric storage water heaters installed in manufactured homes shall have a standby loss not exceeding 43 watts/meter 2 2 (2) All gas and oil-fired automatic storage water heaters shall have a recovery efficiency, E, and a standby loss, S, as described below. The method of test of E and S shall be as described in section 2.7 of Gas Water heaters, Vol. I, Storage Water Heaters with Input/Ratings of 75,000 BTU per hour or less, ANSI Z21.10.1 (CSA Group; incorporated by reference, see § 3280.4), except that for oil-fired units. CF = 1.0, Q = total gallons of oil consumed and H = total heating value of oil in BTU/gallon. Table 1 to Paragraph (d) Storage capacity in gallons Recovery efficiency Standby loss Less than 25 At least 75 percent Not more than 7.5 percent. 25 up to 35 00 Not more than 7 percent. 35 or more 00 Not more than 6 percent. (e) Each space heating, cooling or combination heating and cooling system shall be provided with at least one readily adjustable automatic control for regulation of living space temperature. The control shall be placed a minimum of 3 feet from the vertical edge of the appliance compartment door. It shall not be located on an exterior wall or on a wall separating the appliance compartment from a habitable room. (f) Oil-fired heating equipment. (1) External switches or remote controls which shut off the burner or the flow of oil to the burner, or (2) An emergency disconnect switch to interrupt electric power to the equipment under conditions of excessive temperature. [40 FR 58752, Dec. 17, 1975, as amended at 42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 47 FR 49391, Nov. 1, 1982; 52 FR 4588, Feb. 12, 1987; 52 FR 47553, Dec. 15, 1987; 58 FR 55017, Oct. 25, 1993; 70 FR 72050, Nov. 30, 2005; 78 FR 73988, Dec. 9, 2013; 89 FR 75754, Sept. 16, 2024] § 3280.708 Exhaust duct system and provisions for the future installation of a clothes dryer. (a) Clothes dryers. (i) The exhaust duct system is connected to the clothes dryer, and (ii) A moisture lint exhaust duct system is roughed in and installation instructions are provided in accordance with paragraph (b)(3) or (c) of this section. (2) A clothes dryer moisture-lint exhaust duct shall not be connected to any other duct, vent or chimney. (3) The exhaust duct shall not terminate beneath the manufactured home. (4) Moisture-lint exhaust ducts shall not be connected with sheet metal screws or other fastening devices which extend into the interior of the duct. (5) Moisture-lint exhaust duct and termination fittings shall be installed in accordance with the appliance manufacturer's printed instructions. (b) Provisions for future installation of a gas clothes dryer. (1) The “stubbed in” gas outlet shall be provided with a shutoff valve, the outlet of which is closed by threaded pipe plug or cap; (2) The “stubbed in” gas outlet shall be permanently labeled to identify it for use only as the supply connection for a gas clothes dryer; (3) A moisture lint duct system consisting of a complete access space (hole) through the wall or floor cavity with a cap or cover on the interior and exterior of the cavity secured in such a manner that they can be removed by a common household tool shall be provided. The cap or cover in place shall limit air infiltration and be designed to resist the entry of water or rodents. The manufacturer is not required to provide the moisture-lint exhaust duct or the termination fitting. The manufacturer shall provide written instructions to the owner on how to complete the exhaust duct installation in accordance with provisions of § 3280.708(a)(1) through (5). (c) Provisions for future installation of electric clothes dryers. (1) Provide a roughed in moisture-lint exhaust duct system consisting of a complete access space (hole) through the wall or floor cavity with a cap or cover on the interior and exterior of the cavity which are secured in such a manner that they can be removed by the use of common household tools. The cap or cover in place shall limit air filtration and be designed to resist the entry of water or rodents into the home. The manufacturer is not required to provide the moisture-lint exhaust duct or the termination fitting; (2) Install a receptacle for future connection of the dryer; (3) Provide written instructions on how to complete the exhaust duct installation in accordance with the provisions of paragraphs (a)(1) through (5) of this section. [42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55018, Oct. 25, 1993; 86 FR 2522, Jan. 12, 2021] § 3280.709 Installation of appliances. (a) The installation of each appliance must conform to the terms of its listing and the manufacturer's instructions. Every appliance must be secured in place to avoid displacement. For the purpose of servicing and replacement, each appliance must be both accessible and removable. (1) A direct vent space heating appliance is permitted to be shipped loose for on-site installation in a basement provided the following: (i) The heating appliance is listed for the installation. (ii) Approved installation instructions are provided that include requirements for completion of all gas and electrical connections and provide for the manufacturer's inspection and/or testing of all connections. (iii) Approved instructions are provided to assure connection of the vent and combustion air systems in accordance with § 3280.710(b), and to provide for the manufacturer's inspection of the systems for compliance. (iv) Approved installation and the manufacturer's inspection procedures are provided for the connection of the site-installed heating appliance to the factory-installed circulation air system and return air systems. (2) The procedures must include revisions to assure compliance of the installed systems with § 3280.715. (b) Heat-producing appliances shall be so located that no doors, drapes, or other such material can be placed or swing closer to the front of the appliance than the clearances specified on the labeled appliances. (c) Clearances surrounding heat producing appliances shall not be less than the clearances specified in the terms of their listings. (1) Prevention of storage. The area surrounding heat producing appliances installed in areas with interior or exterior access shall be framed-in or guarded with noncombustible material such that the distance from the appliance to the framing or guarding material is not greater than three inches unless the appliance is installed in compliance with paragraph (c)(2), of this section. When clearance required by the listing is greater than three inches, the guard or frame shall not be closer to the appliance than the distance provided in the listing. (2) Clearance spaces surrounding heat producing appliances are not required to be framed-in or guarded when: (i) A space is designed specifically for a clothes washer or dryer; (ii) Dimensions surrounding the appliance do not exceed three inches; or (iii) The manufacturer affixes either to a side of an alcove or compartment containing the appliance, or to the appliance itself, in a clearly visible location, a 3″ × 5″ adhesive backed plastic laminated label or the equivalent which reads as follows: “Warning” This compartment is not to be used as a storage area. Storage of combustible materials or containers on or near any appliance in this compartment may create a fire hazard. Do not store such materials or containers in this compartment. (d) All fuel-burning appliances, except ranges, ovens, illuminating appliances, clothes dryers, solid fuel-burning fireplaces and solid fuel-burning fireplace stoves, shall be installed to provide for the complete separation of the combustion system from the interior atmosphere of the manufactured home. Combustion air inlets and flue gas outlets shall be listed or certified as components of the appliance. The required separation may be obtained by: (1) The installation of direct vent system (sealed combustion system) appliances, or (2) The installation of appliances within enclosures so as to separate the appliance combustion system and venting system from the interior atmosphere of the manufactured home. There shall not be any door, removable access panel, or other opening into the enclosure from the inside of the manufactured home. Any opening for ducts, piping, wiring, etc., shall be sealed. (e) A forced air appliance and its return-air system shall be designed and installed so that negative pressure created by the air-circulating fan cannot affect its or another appliance's combustion air supply or act to mix products of combustion with circulating air. (1) The air circulating fan of a furnace installed in an enclosure with another fuel-burning appliance shall be operable only when any door or panel covering an opening in the furnace fan compartment or in a return air plenum or duct is in the closed position. This does not apply if both appliances are direct vent system (sealed combustion system) appliances. (2) If a warm air appliance is installed within an enclosure to conform to § 3280.709(d)(2), each warm-air outlet and each return air inlet shall extend to the exterior of the enclosure. Ducts, if used for that purpose, shall not have any opening within the enclosure and shall terminate at a location exterior to the enclosure. (3) Cooling coils installed as a portion of, or in connection with, any forced-air furnace shall be installed on the downstream side unless the furnace is specifically otherwise listed. (4) An air conditioner evaporator section shall not be located in the air discharge duct or plenum of any forced-air furnace unless the manufactured home manufacturer has complied with certification required in § 3280.511. (5) If a cooling coil is installed with a forced-air furnace, the coil shall be installed in accordance with its listing. When a furnace-coil unit has a limited listing, the installation must be in accordance with that listing. (6) When an external heating appliance or combination cooling/heating appliance is to be field installed, the home manufacturer shall make provision for proper location of the connections to the supply and return air systems. The manufacturer is not required to provide said appliance(s). The preparation by the manufacturer for connection to the home's supply and return air system shall include all fittings and connection ducts to the main duct and return air system such that the installer is only required to provide: (i) The appliance; (ii) Any appliance connections to the home; and (iii) The connecting duct between the external appliance and the fitting installed on the home by the manufacturer. The above connection preparations by the manufacturer do not apply to supply or return air systems designed only to accept external cooling (i.e., self contained air conditioning systems, etc.) (7) The installation of a self contained air conditioner comfort cooling appliance shall meet the following requirements: (i) The installation on a duct common with an installed heating appliance shall require the installation of an automatic damper or other means to prevent the cooled air from passing through the heating appliance unless the heating appliance is certified or listed for such application and the supply system is intended for such an application. (ii) The installation shall prevent the flow of heated air into the external cooling appliance and its connecting ducts to the manufactured home supply and return air system during the operation of the heating appliance installed in the manufactured home. (iii) The installation shall prevent simultaneous operation of the heating and cooling appliances. (f) Vertical clearance above cooking top. (g) Solid fuel burning fireplaces and fireplace stoves listed for residential use may be installed in manufactured homes provided they and their installation conform to paragraphs (g)(1)(i) through (vii) of this section. A fireplace or fireplace stove is not to be considered as a heating facility for determining compliance with subpart F of this part. (1) A solid fuel-burning fireplace or fireplace stove shall be equipped with integral door(s) or shutter(s) designed to close the fireplace or fireplace stove fire chamber opening and shall include complete means for venting through the roof, a combustion air inlet, a hearth extension, and means to securely attach the fireplace or the fireplace stove to the manufactured home structure. The installation shall conform to the following paragraphs (g)(1) (i) to (vii) inclusive: (i) A listed factory-built chimney designed to be attached directly to the fireplace or fireplace stove shall be used. The listed factory built chimney shall be equipped with and contain as part of its listing a termination device(s) and a spark arrester(s). (ii) A fireplace or fireplace stove, air intake assembly, hearth extension and the chimney shall be installed in accordance with the terms of their listings and their manufacturer's instructions. (iii) The combustion air inlet shall conduct the air directly into the fire chamber and shall be designed to prevent material from the hearth dropping onto the area beneath the manufactured home. (iv) The fireplace or fireplace stove shall not be installed in a sleeping room. (v) Hearth extension shall be of noncombustible material not less than 3/8 (vi) The label on each solid fuel-burning fireplace and solid fuel-burning fireplace stove shall include the following wording: For use with solid fuel only. (vii) The chimney shall extend at least three feet above the part of the roof through which it passes and at least two feet above the highest elevation of any part of the manufactured home within 10 feet of the chimney. Portions of the chimney and termination that exceed an elevation of 13 1/2 (2) [Reserved] (h) A corrosion-resistant water drip collection and drain pan must be installed under each storage tank-type water heater or a hot water storage tank that will allow water leaking from the water heater to drain to the exterior of the manufactured home, or to a drain. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 44 FR 66195, Nov. 19, 1979; 58 FR 55018, Oct. 25, 1993; 70 FR 72050, Nov. 30, 2005; 86 FR 2523, Jan. 12, 2021; 89 FR 75755, Sept. 16, 2024] § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by § 3280.707(b) shall be accomplished by one or more of the methods given in (a)(1) and (2) of this section: (1) An integral vent system listed or certified as part of the appliance. (2) A venting system consisting entirely of listed components, including roof jack, installed in accordance with the terms of the appliance listing and the appliance manufacturer's instructions. (b) Venting and combustion air systems shall be installed in accordance with the following: (1) Components shall be securely assembled and properly aligned at the factory in accordance with the appliance manufacturer's instructions except vertical or horizontal sections of a fuel fired heating appliance venting system that extend beyond the roof line or outside the wall line may be installed at the site. Sectional venting systems shall be listed for such applications and installed in accordance with the terms of their listings and manufacturers' instructions. In cases where sections of the venting system are removed for transportation, a label shall be permanently attached to the appliance indicating the following: Sections of the venting system have not been installed. Warning-do not operate the appliance until all sections have been assembled and installed in accordance with the manufacturer's instructions. (2) Draft hood connectors shall be firmly attached to draft hood outlets or flue collars by sheet metal screws or by equivalent effective mechanical fasteners. (3) Every joint of a vent, vent connector, exhaust duct and combustion air intake shall be secure and in alignment. (c) Venting systems shall not terminate underneath a manufactured home. (d) Venting systems of fuel-burning appliances must terminate at least three feet above any motor-driven air intake discharging into habitable rooms when located within ten feet of the air intake. (e) The area in which cooking appliances are located shall be ventilated by a metal duct which may be single wall, not less than 12.5 square inches in cross-sectional area (minimum dimension shall be two inches) located above the appliance(s) and terminating outside the manufactured home, or by listed mechanical ventilating equipment discharging outside the home, that is installed in accordance with the terms of listing and the manufacturer's instructions. Gravity or mechanical ventilation shall be installed within a horizontal distance of not more than ten feet from the vertical front of the appliance(s). (f) Mechanical ventilation which exhausts directly to the outside atmosphere from the living space of a home shall be equipped with an automatic or manual damper. Operating controls shall be provided such that mechanical ventilation can be separately operated without directly energizing other energy consuming devices. [49 FR 32012, Aug. 9, 1984, as amended at 58 FR 55018, Oct. 25, 1993; 86 FR 2523, Jan. 12, 2021] § 3280.711 Instructions. Operating instructions for each appliance must be provided with the homeowner's manual. An additional copy of the operating instructions must be provided with each appliance unless the appliance is affixed with a permanent Quick Response (QR) Code. [89 FR 75755, Sept. 16, 2024] § 3280.712 Marking. (a) Information on clearances, input rating, lighting and shutdown shall be attached to the appliances with the same permanence as the nameplate, and so located that it is easily readable when the appliance is properly installed or shutdown for transporting of manufactured home. (b) Each fuel-burning appliance shall bear permanent marking designating the type(s) of fuel for which it is listed. § 3280.713 Accessibility. Every appliance shall be accessible for inspection, service, repair, and replacement without removing permanent construction. For those purposes, inlet piping supplying the appliance shall not be considered permanent construction. Sufficient room shall be available to enable the operator to observe the burner, control, and ignition means while starting the appliance. [58 FR 55018, Oct. 25, 1993] § 3280.714 Appliances, cooling. (a) Every air conditioning unit or a combination air conditioning and heating unit shall be listed or certified by a nationally recognized testing agency for the application for which the unit is intended and installed in accordance with the terms of its listing. (1) Mechanical air conditioners shall be rated in accordance with the ANSI/AHRI Standard 210/240 with Addenda 1 and 2 (incorporated by reference, see § 3280.4) and certified by AHRI or other nationally recognized testing agency capable of providing follow-up service. (i) Electric motor-driven unitary air-cooled air conditioners and heat pumps in the cooling mode with rated capacity less than 65,000 BTU/hour (19,045 watts), when rated at AHRI standard rating conditions in ANSI/AHRI Standard 210/240 with Addenda 1 and 2 (incorporated by reference, see § 3280.4), must have seasonal energy efficiency (SEER) values not less than as specified in 10 CFR part 430, Energy Conservation Program for Consumer Products: Central Air Conditioners and Heat Pumps Energy Conservation Standards. (ii) Heat pumps must be certified to comply with all requirements of the ANSI/AHRI Standard 210/240 with Addenda 1 and 2 (incorporated by reference, see § 3280.4). Electric motor-driven vapor compression heat pumps with supplemental electrical resistance heat must be sized to provide by compression at least 60 percent of the calculated annual heating requirements for the manufactured home being served. A control must be provided and set to prevent operation of supplemental electrical resistance heat at outdoor temperatures above 40 °F (4 °C), except for defrost conditions. Electric motor-driven vapor compression heat pumps with supplemental electric resistance heat conforming to ANSI/AHRI Standard 210/240 with Addenda 1 and 2, must have Heating Season Performance Factor (HSPF) efficiencies not less than as specified in the 10 CFR part 430, Energy Conservation Program for Consumer Products: Central Air Conditioners and Heat Pumps Energy Conservation Standards. (iii) Electric motor-driven vapor compression heat pumps with supplemental electric resistance heat conforming to ANSI/AHRI Standard 210/240 with Addenda 1 and 2 (incorporated by reference, see § 3280.4), shall show coefficient of performance ratios not less than shown below: Table 1 to Paragraph (a)(1)(iii) Temperature degrees Fahrenheit Coefficient of 47 2.5 17 1.7 0 1.0 (2) Gas fired absorption air conditioners must be listed or certified in accordance with ANSI Z21.40.1, (CSA Group; incorporated by reference, see § 3280.4), and certified by a nationally recognized testing agency capable of providing follow-up service. (3) Direct refrigerating systems serving any air conditioning or comfort-cooling system installed in a manufactured home shall employ a type of refrigerant that ranks no lower than Group 5 in the Underwriters' Laboratories, Inc. “Classification of Comparative Life Hazard of Various Chemicals.” (4) When a cooling or heat pump coil and air conditioner blower are installed with a furnace or heating appliance, they shall be tested and listed in combination for heating and safety performance by a nationally recognized testing agency. (5) Cooling or heat pump indoor coils and outdoor sections shall be certified, listed and rated in combination for capacity and efficiency by a nationally recognized testing agency(ies). Rating procedures shall be based on U.S. Department of Energy test procedures. (b) Installation and instructions. (2) Operating instructions shall be provided with the appliance. (c) Fuel-burning air conditioners shall also comply with § 280.707. (d) The appliance rating plate shall be so located that it is easily readable when the appliance is properly installed. (e) Every installed appliance shall be accessible for inspection, service, repair and replacement without removing permanent construction. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55018, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73989, Dec. 9, 2013; 89 FR 75755, Sept. 16, 2024] § 3280.715 Circulating air systems. (a) Supply system. Table 1 to Paragraph (a) 1 Duct type Diameter 14 in. Width over Round 0.013 0.016 Enclosed rectangular 0.013 0.016 Exposed rectangular 0.016 0.019 1 (2) Sizing of ducts for heating. (ii) When an evaporator-coil specifically designed for the particular furnace is installed between the furnace and the duct plenum, the total static pressure shall be measured downstream of the coil in accordance with the appliance label and shall not exceed 90 percent of that shown on the label of the appliance. (iii) When any other listed air-cooler coil is installed between the furnace and the duct plenum, the total static pressure shall be measured between the furnace and the coil and it shall not exceed 90 percent of that shown on the label of the furnace. (iv) The minimum dimension of any branch duct shall be at least 1 1/2 1/2 (3) Sizing of ducts. (ii) The refrigerated air cooling supply duct system including registers must be capable of handling at least 300 cfm per 10,000 btuh with a static pressure no greater than 0.3 inches of water when measured at room temperature. In the case of application of external self contained comfort cooling appliances or the cooling mode of combination heating/cooling appliances, either the external ducts between the appliance and the manufactured home supply system shall be considered part of, and shall comply with the requirements for the refrigerated air cooling supply duct system, or the connecting duct between the external appliance and the mobile supply duct system shall be a part of the listed appliance. The minimum dimension of any branch duct shall be at least 1 1/2 1/2 (4) Airtightness of supply duct systems. 1/10 (5) Expandable or multiple manufactured home connections. (ii) The manufacturer must provide installation instructions for supporting, mechanically fastening, sealing, and insulating each crossover duct. The instructions must indicate that no portion of the crossover duct is to be in contact with the ground, and must describe the means to support the duct without compressing the insulation and restricting airflow. (6) Air supply ducts shall be insulated with material having an effective thermal resistance (R) of not less than 4.0 unless they are within manufactured home insulation having a minimum effective value of R-4.0 for floors or R-6.0 for ceilings. (7) Unless installed in a basement, supply and return ducts, fittings, and crossover duct plenums exposed directly to outside air, such as those under-chassis crossover ducts or ducts connecting external heating, cooling, or combination heating/cooling appliances, must be insulated with material having a minimum thermal resistance of R-8 in all Thermal Zones. All such insulating materials must have a continuous vapor barrier retarder having a perm rating of not more than 1 perm. Where ducts are exposed underneath the manufactured home, they must comply with paragraph (a)(5)(ii) of this section, and shall be listed for exterior use. (b) Return air systems Return air openings. (2) Duct material. (i) Portions of return ducts directly above the heating surfaces, or closer than 2 feet from the outer jacket or casing of the furnace shall be constructed of metal in accordance with § 3280.715(a)(1) or shall be listed Class 0 or Class 1 air ducts. (ii) Return ducts, except as required by paragraph (a) of this section, shall be constructed of one-inch (nominal) wood boards (flame spread classification of not more than 200), other suitable material no more flammable than one-inch board or in accordance with § 3280.715(a)(1). (iii) The interior of combustible ducts shall be lined with noncombustible material at points where there might be danger from incandescent particles dropped through the register or furnace such as directly under floor registers and the bottom return. (iv) Factory made air ducts used for connecting external heating, cooling or combination heating/cooling appliances to the supply system and return air system of a manufactured home shall be listed by a nationally recognized testing agency. Ducts applied to external heating appliances or combination heating/cooling appliances supply system outlets shall be constructed of metal in accordance with § 3280.715(a)(1) or shall be listed Class 0 or Class 1 air ducts for those portions of the duct closer than 2 feet from the outer casing of the appliance. (v) Ducts applied to external appliances shall be resistant to deteriorating environmental effects, including but not limited to ultraviolet rays, cold weather, or moisture and shall be resistant to insects and rodents. (3) Sizing. (4) Permanent uncloseable openings. 1/2 (c) Joints and seams. (d) Supports and protection. (e) Registers and grilles. (1) Be made of a material classified 94V-0 or 94V-1, when tested as described in UL 94-1996, with 2001 revisions, Test for Flammability of Plastic Materials for Parts in Devices and Appliances, Fifth Edition; and (2) Floor registers or grilles shall resist without structural failure a 200 lb. concentrated load on a 2-inch diameter disc applied to the most critical area of the exposed face of the register or grille. For this test the register or grille is to be at a temperature of not less than 165 °F and is to be supported in accordance with the manufacturer's instructions. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4589, Feb. 12, 1987; 58 FR 55019, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73989, Dec. 9, 2013; 89 FR 75755, Sept. 16, 2024] Subpart I—Electrical Systems § 3280.801 Scope. (a) This subpart I incorporates by reference NFPA 70 (incorporated by reference, see § 3280.4) including Part II of Article 550 of NFPA 70, and covers the electrical conductors and equipment installed within or on manufactured homes and the conductors that connect manufactured homes to a supply of electricity. However, Articles 550.4(A) and 550.4(B) of NFPA 70 shall not apply. (b) In addition to the requirements of this part and Part II of Article 550 of NFPA 70, the applicable portions of other Articles of NFPA 70 referenced in this part must be followed for electrical installations in manufactured homes. The use of arc-fault breakers under the NFPA 70, are only required for general lighting circuits. Smoke alarms installed on a dedicated circuit do not require arc fault protection. Wherever arc-fault breakers are provided, such use must be in accordance with NFPA 70. Wherever the requirements of these standards differ from NFPA 70, these standards apply. (c) The provisions of this standard apply to manufactured homes intended for connection to a wiring system nominally rated 120/240 volts, 3-wire AC, with grounded neutral. (d) All electrical materials, devices, appliances, fittings and other equipment shall be listed or labeled by a nationally recognized testing agency and shall be connected in an approved manner when in service. (e) Aluminum conductors, aluminum alloy conductors, and aluminum core conductors such as copper clad aluminum; are not acceptable for use in branch circuit wiring in manufactured homes. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55019, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 71 FR 19639, Apr. 17, 2006; 89 FR 75756, Sept. 16, 2024] § 3280.802 Definitions. (a) The following definitions are applicable to subpart I only. (1) Accessible As applied to equipment readily accessible. (ii) ( As applied to wiring methods concealed exposed (2) Air conditioning or comfort cooling equipment (3)(i) Appliance (ii) Appliance, fixed (iii) Appliance, portable (iv) Appliance, stationary (4) Attached accessory building or structure (5) Attachment plug (plug cap) (cap) (6) Bonding (7) Branch circuit (ii) Branch circuit—appliance (iii) Branch circuit—general purpose (iv) Branch circuit—individual (8) Cabinet (9) Circuit breaker (10) Concealed accessible (As applied to wiring methods) (11) Connector, pressure (solderless) (12) Dead front (as applied to switches, circuit-breakers, switchboards, and distribution panelboard) (13) Demand factor (14) Device (15) Disconnecting means (16) Distribution panelboard (17) Enclosed (18) Equipment (19) Exposed accessible concealed. (ii) (As applied to wiring method Accessible (as applied to wiring methods) (20) Externally operable (21) Feeder assembly (22) Fitting (23) Ground (24) Grounded (25) Grounded conductor (26) Grounding conductor (27) Guarded (28) Isolated (29) Laundry area (30) Lighting outlet (31) Manufactured home accessory building or structure (32) Manufactured home service equipment (33) Outlet (34) Panelboard (35) Raceway (36) Raintight (37) Readily accessible Accessible. (38) Receptacle (39) Receptacle outlet (40) Utilization equipment (41) Voltage (of a circuit) (42) Weatherproof (b) [Reserved] [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 78 FR 73989, Dec. 9, 2013; 86 FR 2523, Jan. 12, 2021; 89 FR 75756, Sept. 16, 2024] § 3280.803 Power supply. (a) The power supply to the manufactured home must be a feeder assembly consisting of not more than one listed 50 ampere manufactured home power supply cord, or a permanently installed circuit. A manufactured home that is factory equipped with gas or oil-fired heating equipment and cooking appliances is permitted to be provided with a listed power supply cord rated 40 amperes. This section does not apply to multi-dwelling unit manufactured homes. (b) If the manufactured home has a power-supply cord, it shall be permanently attached to the distribution panelboard or to a junction box permanently connected to the distribution panelboard, with the free end terminating in an attachment plug cap. (c) Cords with adapters and pigtail ends, extension cords, and similar items shall not be attached to, or shipped with, a manufactured home. (d) A suitable clamp or the equivalent must be provided at the distribution panelboard knockout to afford strain relief for the cord to prevent strain from being transmitted to the terminals when the power supply cord is handled in its intended manner. (e) The cord shall be of an approved type with four conductors, one of which shall be identified by a continuous green color or a continuous green color with one or more yellow stripes for use as the grounding conductor. (f) The attachment plug cap must be a 3-pole, 4-wire, grounding type, rated 50 amperes, 125/250 volts, intended for use with the 50-ampere, 125/250-volt receptacle configuration, as shown below. The cap must be listed, by itself or as part of a power-supply cord assembly, for the purpose, and must be molded to or installed on the flexible cord so that it is secured tightly to the cord at the point where the cord enters the attachment plug cap. If a right-angle cap is used, the configuration must be so oriented that the grounding member is farthest from the cord. (g) The overall length of a power-supply cord, measured from the end of the cord, including bared leads, to the face of the attachment-plug cap shall not be less than 21 feet and shall not exceed 36 1/2 (h) The power supply cord shall bear the following marking: “For use with manufactured homes—40 amperes” or “For use with manufactured homes—50 amperes.” (i) Where the cord passes through walls or floors, it must be protected by means of conduits and bushings or the equivalent. The cord is permitted to be installed within the manufactured home walls, provided that a continuous raceway having a maximum size of 1 1/4 (j) Permanent provisions shall be made for the protection of the attachment-plug cap of the power supply cord and any connector cord assembly or receptacle against corrosion and mechanical damage if such devices are in an exterior location while the manufactured home is in transit. (k) Where the calculated load exceeds 50 amperes or where a permanent feeder is used, the supply shall be by means of: (1) One mast weatherhead installation installed in accordance with Article 230 of NFPA 70 (incorporated by reference, see § 3280.4), containing four continuous insulated, color-coded, feeder conductors, one of which shall be an equipment grounding conductor; or (2) A listed metal raceway or listed rigid nonmetallic conduit from the disconnecting means in the manufactured home to the underside of the manufactured home, with provisions for the attachment of a suitable junction box or fitting to the raceway on the underside of the manufactured home. The manufacturer must provide written installation instructions stating the proper feeder conductor sizes for the raceway and the size of the junction box to be used; or (3) Service equipment installed in or on the manufactured home, provided that all of the following conditions are met: (i) In its written installation instructions, the manufacturer must include information indicating that the home must be secured in place by an anchoring system or installed on and secured to a permanent foundation; (ii) The installation of the service equipment complies with Article 230 of NFPA 70 (incorporated by reference, see § 3280.4). Exterior service equipment or the enclosure in which it is to be installed must be weatherproof, and conductors must be suitable for use in wet locations; (iii) Bonding and grounding of the service must be in accordance with Article 250 of NFPA 70 (incorporated by reference, see § 3280.4); (iv) The manufacturer must include in its installation instructions one method of grounding the service equipment at the installation site. The instructions must clearly state that other methods of grounding are found in Article 250 of NFPA 70; (v) The minimum size grounding electrode conductor must be specified in the instructions; and (vi) A red warning label must be mounted on or adjacent to the service equipment. The label must state the following: WARNING—DO NOT PROVIDE ELECTRICAL POWER UNTIL THE GROUNDING ELECTRODE(S) IS INSTALLED AND CONNECTED (SEE INSTALLATION INSTRUCTIONS). [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4589, Feb. 12, 1987; 58 FR 55019, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73990, Dec. 9, 2013; 89 FR 75756, Sept. 16, 2024] § 3280.804 Disconnecting means and branch-circuit protective equipment. (a) The branch-circuit equipment is permitted to be combined with the disconnecting means as a single assembly. Such a combination is permitted to be designated as a distribution panelboard. If a fused distribution panelboard is used, the maximum fuse size for the mains shall be plainly marked, with the lettering at least 1/4 (b) Plug fuses and fuseholders shall be tamper-resistant, Type “S,” enclosed in dead-front fuse panelboards. Electrical distribution panels containing circuit breakers shall also be dead-front type. (c) A single disconnecting means must be provided in each dwelling unit, consisting of a circuit breaker, or a switch and fuses and its accessories, installed in a readily accessible location near the point of entrance of the supply cord or conductors into the dwelling unit. (d) The disconnecting equipment shall have a rating suitable for the connected load. The distribution equipment, either circuit breaker or fused type, shall be located a minimum of 24 inches from the bottom of such equipment to the floor level of the manufactured home. (e) A distribution panelboard employing a main circuit breaker must be rated not less than 50 amperes and employ a 2-pole circuit breaker rated 40 amperes for a 40-ampere supply cord, or 50 amperes for a 50-ampere supply cord. A distribution panelboard employing a disconnect switch and fuses must be rated not less than 60 amperes and must employ a single, 2-pole fuseholder rated not less than 60-amperes with 40- or 50-ampere main fuses for 40- or 50-ampere supply cords, respectively. The outside of the distribution panelboard must be plainly marked with the fuse size. (f) The distribution panelboard must be located in an accessible location, and must not be located in a bathroom or a clothes closet. A clear working space at least 30 inches wide and 30 inches in front of the distribution panelboard must be provided. This space must extend from the floor to the top of the distribution panelboard. Where used as switches, circuit breakers must be installed so that the center of the grip of the operating handle of the circuit breaker, when in its highest position, will not be more than 6 feet, 7 inches above the floor. (g) Branch-circuit distribution equipment must be installed in each dwelling unit and must include overcurrent protection for each branch circuit consisting of either circuit breakers or fuses. (1) The branch circuit overcurrent devices shall be rated: (i) Not more than the circuit conductors; and (ii) Not more than 150 percent of the rating of a single appliance rated 13.3 amperes or more which is supplied by an individual branch circuit; but (iii) Not more than the fuse size marked on the air conditioner or other motor-operated appliance. (2) [Reserved] (h) A 15-ampere multiple receptacle shall be acceptable when connected to a 20-ampere laundry circuit. (i) When circuit breakers are provided for branch-circuit protection 240 circuits shall be protected by 2-pole common or companion trip, or handle-tied paired circuit breakers. (j) A 3 inch by 1-3/4 inch minimum size tag made of etched, metal-stamped or embossed brass, stainless steel, anodized or alclad aluminum not less than 0.020 inch thick, or other approval material (e.g., 0.005 inch plastic laminates) shall be permanently affixed on the outside adjacent to the feeder assembly entrance and shall read: This connection for 120/240 Volt, 3-Pole, 4-Wire, 60 Hertz, ________ Ampere Supply. The correct ampere rating shall be marked on the blank space. (k) When a home is provided with installed service equipment, a single disconnecting means for disconnecting the branch circuit conductors from the service entrance conductors must be provided in accordance with Article 230, Part VI of NFPA 70 (incorporated by reference, see § 3280.4). The disconnecting means shall be listed for use as service equipment. The disconnecting means may be combined with the disconnect required by paragraph (c) of this section. The disconnecting means shall be rated not more than the ampere supply or service capacity indicated on the tag required by paragraph (l) of this section. (l) When a home is provided with installed service equipment, the electrical nameplate required by § 3280.804(j) shall read: “This connection for 120/240 volt, 3 pole, 3 wire, 60 Hertz, ________ Ampere Supply.” The correct ampere rating shall be marked in the blank space. (m) A service distribution panel must be factory installed and connected to the subpanels on multi-dwelling unit manufactured homes. [40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4589, Feb. 12, 1987; 58 FR 55019, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73990, Dec. 9, 2013; 89 FR 75756, Sept. 16, 2024] § 3280.805 Branch circuits required. (a) The number of branch circuits required shall be determined in accordance with the following: (1) Lighting. Example 1 to Paragraph (a)(1) # of Lighting Circuits = (3 × L × W × # of Stories)/(120 × (15 or 20)) (2) Small Appliances. (3) General appliances Including furnace, water heater, range, and central or room air conditioner, etc. (i) The ampere rating of fixed appliances must not exceed 50 percent of the circuit rating if lighting outlets are on the same circuit (receptacles in the kitchen, dining area, and laundry are not considered to be lighting outlets); (ii) For fixed appliances on a circuit without lighting outlets, the sum of rated amperes shall not exceed the branch-circuit rating. Motor loads or other continuous duty loads shall not exceed 80 percent of the branch circuit rating. (iii) The rating of a single cord and plug connected appliances on a circuit having no other outlets, shall not exceed 80 percent of the circuit rating. (iv) The rating of the range branch circuit is based on the range demand as specified for ranges in § 3280.811(a)(5). For central air conditioning, see Article 440 of NFPA 70 (incorporated by reference, see § 3280.4). (v) Where a laundry area is provided, a 20 ampere branch circuit shall be provided to supply laundry receptacle outlets. This circuit shall have no other outlets. See § 3280.806(a)(7). (vi) Bathroom receptacle outlets must be supplied by at least one 20-ampere branch circuit. Such circuits must have no other outlets, except that it is permissible to place the receptacle outlet for a heat tape or pipe heating cable required by § 3280.806(d)(10) on a bathroom circuit. (See § 3280.806(b).) (b) [Reserved] [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55020, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73991, Dec. 9, 2013; 89 FR 75757, Sept. 16, 2024] § 3280.806 Receptacle outlets. (a) All receptacle outlets shall be: (1) Of grounding type; (2) Installed according to Article 406.3 of NFPA 70 (incorporated by reference, see § 3280.4). (3) Except when supplying specific appliances, be parallel-blade, 15-ampere, 125-volt, either single or duplex. (b) All 125-volt, single-phase, 15- and 20-ampere receptacle outlets installed outdoors, or in compartments accessible from outside the manufactured home, and in bathrooms, including receptacles in light fixtures, must have ground-fault circuit-interrupter protection for personnel. Ground-fault circuit-interrupter protection for personnel must be provided for receptacles serving countertops in kitchens and receptacle outlets located within 6 feet of a wet bar sink, except for receptacles installed for appliances in dedicated spaces, such as dishwashers, disposals, refrigerators, freezers, and laundry equipment. (c) There shall be an outlet of the grounding type for each cord-connected fixed appliance installed. (d) Receptacle outlets required. (1) Over or adjacent to counter tops in the kitchen (at least one on each side of the sink if counter tops are on each side and 12 inches or over in width). (2) Adjacent to the refrigerator and free-standing gas-range space. A duplex receptacle may serve as the outlet for a countertop and a refrigerator. (3) At counter top spaces for built-in vanities. (4) At counter top spaces under wall-mounted cabinets. (5) In the wall, at the nearest point where a bar type counter attaches to the wall. (6) In the wall at the nearest point where a fixed room divider attaches to the wall. (7) In laundry areas within 6 feet of the intended location of the appliance(s). (8) At least one receptacle outlet shall be installed outdoors. Additional outdoor receptacles shall be installed in accordance with Article 210.52(E)(3) of NFPA 70 (incorporated by reference, see § 3280.4), except those balconies, decks, or porches with an area of less than 20 square feet are not required to have an additional receptacle installed. (9) At least one wall receptacle outlet shall be installed in bathrooms within 36 inches (914 mm) of the outside edge of each basin. The receptacle outlet must be located on a wall that is adjacent to the basin location. This receptacle is in addition to any receptacle that is part of a lighting fixture or appliance. The receptacle must not be enclosed within a bathroom cabinet or vanity. (10) On the underside of the home for the connection of pipe heating cable(s) or heat tape(s), and the outlet must: (i) Be located within 2 feet of the cold water inlet; (ii) Be connected to an interior branch circuit, other than a small appliance branch circuit; (iii) Be located on a circuit where all of the outlets are on the load side of the ground-fault circuit-interrupter protection for personnel; and (iv) Not be considered as the receptacle outlet required by paragraph (8) of this section. (11) Receptacle outlets are not required in the following locations: (i) Wall space occupied by built-in kitchen or wardrobe cabinets, (ii) Wall space behind doors which may be opened fully against a wall surface, (iii) Room dividers of the lattice type, less than 8 feet long, not solid within 6 inches of the floor, (iv) Wall space afforded by bar type counters. (e) Receptacle outlets shall not be installed in or within reach (30 inches) of a shower or bathtub space. (f) Receptacle outlets shall not be installed above electric baseboard heaters. (g) Receptacles must not be in a face-up position in any countertop. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55020, Oct. 25, 1993; 70 FR 72052, Nov. 30, 2005; 78 FR 73991, Dec. 9, 2013; 89 FR 75757, Sept. 16, 2024] § 3280.807 Fixtures and appliances. (a) Electrical materials, devices, appliances, fittings, and other equipment installed, intended for use in, or attached to the manufactured home shall be approved for the application and shall be connected in an approved manner when in service. Facilities shall be provided to securely fasten appliances when the manufactured home is in transit. (See § 3280.809.) (b) Specifically listed pendant-type fixtures or pendant cords shall be permitted in manufactured homes. (c) Where a lighting fixture is installed over a bathtub or in a shower stall, it must be listed for wet locations. See also Article 410.410(D) of NFPA 70 (incorporated by reference, see § 3280.4). (d) The switch for shower lighting fixtures and exhaust fans located over a tub or in a shower stall shall be located outside the tub shower space. (See § 3280.806(e).) (e) Any combustible wall or ceiling finish exposed between the edge of a fixture canopy, or pan and an outlet box shall be covered with non-combustible or limited combustible material. (f) Every appliance shall be accessible for inspection, service, repair, or replacement without removal of permanent construction. (g) In bathrooms, ceiling-mounted lighting fixtures and wall-mounted lighting fixtures must not be controlled by the same switch. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 35543, Sept. 22, 1987; 58 FR 55020, Oct. 25, 1993; 70 FR 72052, Nov. 30, 2005; 78 FR 73991, Dec. 9, 2013; 86 FR 2523, Jan. 12, 2021; 89 FR 75757, Sept. 16, 2024] § 3280.808 Wiring methods and materials. (a) Except as specifically permitted by this part, the wiring methods and materials specified in NFPA 70 (incorporated by reference, see § 3280.4) must be used in manufactured homes. (b) Nonmetallic outlet boxes shall be acceptable only with nonmetallic cable. (c) Nonmetallic cable located 15 inches or less above the floor, if exposed, shall be protected from physical damage by covering boards, guard strips, or conduit. Cable likely to be damaged by stowage shall be so protected in all cases. (d) Nonmetallic sheathed cable shall be secured by staples, straps, or similar fittings so designed and installed as not to injure any cable. Cable shall be secured in place at intervals not exceeding 4 1/2 (e) Metal-clad and nonmetallic cables shall be permitted to pass through the centers of the wide side of 2-inch by 4-inch studs. However, they shall be protected where they pass through 2-inch by 2-inch studs or at other studs or frames where the cable or armor would be less than 1 1/2 (f) Where metal faceplates are used, they must be effectively grounded. (g) If the range, clothes dryer, or similar appliance is connected by metalclad cable or flexible conduit, a length of not less than three feet of free cable or conduit shall be provided to permit moving the appliance. Type NM or Type SE cable shall not be used to connect a range or a dryer. This shall not prohibit the use of Type NM or Type SE cable between the branch circuit overcurrent protective device and a junction box or range or dryer receptacle. (h) Where rigid metal conduit or intermediate metal conduit is terminated at an enclosure with a locknut and bushing connection, two locknuts must be provided, one inside and one outside of the enclosure. Rigid nonmetallic conduit or electrical nonmetallic tubing is permitted. All cut ends of conduit and tubing must be reamed or otherwise finished to remove rough edges. (i) Switches must be rated as follows: (1) For lighting circuits, switches must be rated not less than 10 amperes, 120 to 125 volts, and in no case less than the connected load. (2) For motors or other loads, switches shall have ampere or horsepower ratings, or both, adequate for loads controlled. (An “AC general-use” snap switch shall be permitted to control a motor 2 horsepower or less with full-load current not over 80 percent of the switch ampere rating). (j) At least 4 inches of free conductor shall be left at each outlet box except where conductors are intended to loop without joints. (k) Where outdoor or under-chassis line voltage (120 volts, nominal or higher) wiring is exposed to moisture or subject to physical damage, it must be protected by a conduit or raceway approved for use in wet locations. The conductors must be suitable for use in wet locations. (l) Outlet boxes of dimensions less than those required in table 314.16(A) of NFPA 70 (incorporated by reference, see § 3280.4), are permitted provided the box has been tested and approved for that purpose. (m) Boxes, fittings, and cabinets shall be securely fastened in place, and shall be supported from a structural member of the home, either directly or by using a substantial brace. Snap-in type boxes provided with special wall or ceiling brackets that securely fasten boxes in walls or ceilings shall be permitted. (n) Outlet boxes must fit closely to openings in combustible walls and ceilings and must be flush with the finish surface or project therefrom. In walls and ceilings of noncombustible material, outlet boxes and fittings must be installed so that the front edge of the box or fitting will not be set back from the finished surface more than 1/4 1/8 (o) Appliances having branch-circuit terminal connections which operate at temperatures higher than 60 °C (140 °F) shall have circuit conductors as described in paragraphs (p) (1) and (2) of this section: (1) Branch-circuit conductors having an insulation suitable for the temperature encountered shall be permitted to run directly to the appliance. (2) Conductors having an insulation suitable for the temperature encountered may be run from the appliance terminal connections to a readily accessible outlet box placed at least one foot from the appliance. If provided, these conductors must be in a suitable raceway or Type AC or MC cable, of at least 18 inches but not more than 6 feet in length. (p) A substantial brace for securing a box, fitting, or cabinet must be as described in Article 314.23(B) of NFPA 70 (incorporated by reference, see § 3280.4), or the brace, including the fastening mechanism to attach the brace to the home structure, must withstand a force of 50 lbs. applied to the brace at the intended point(s) of attachment for the box in a direction perpendicular to the surface on which the box is installed. (q) Where the sheathing of NM cable has been cut or damaged and visual inspection reveals that the conductor and its insulation has not been damaged, it shall be permitted to repair the cable sheath with electrical tape which provides equivalent protection to the sheath. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55020, Oct. 25, 1993; 70 FR 72052, Nov. 30, 2005; 78 FR 73991, Dec. 9, 2013; 89 FR 75757, Sept. 16, 2024] § 3280.809 Grounding. (a) General. (b) Insulated neutral. (2) Connection of ranges and clothes dryers with 120/240 volt, 3-wire ratings shall be made with 4 conductor cord and 3 pole, 4-wire grounding type plugs, or by type AC metal clad conductors enclosed in flexible metal conduit. For 120 volt rated devices a 3-conductor cord and a 2-pole, 3-wire grounding type plug shall be permitted. (c) Equipment grounding means. (2) In the electrical system, all exposed metal parts, enclosures, frames, lamp fixture canopies, etc., shall be effectively bonded to the grounding terminal or enclosure of the distribution panelboard. (3) Cord-connected appliances, such as washing machines, clothes dryers, refrigerators, and the electrical system of gas ranges, etc., shall be grounded by means of an approved cord with grounding conductor and grounding-type attachment plug. (d) Bonding of noncurrent-carrying metal parts. (2) Grounding terminals shall be of the solderless type and approved as pressure-terminal connectors recognized for the wire size used. Star washers or other approved paint-penetrating fitting shall be used to bond terminals to chassis or other coated areas. The bonding conductor shall be solid or stranded, insulated or bare and shall be No. 8 copper minimum, or equal. The bonding conductor shall be routed so as not to be exposed to physical damage. Protection can be afforded by the configuration of the chassis. (3) Metallic gas, water and waste pipes and metallic air-circulating ducts shall be considered bonded if they are connected to the terminal on the chassis (see § 3280.809) by clamps, solderless connectors, or by suitable grounding-type straps. (4) Any metallic roof and exterior covering shall be considered bonded if (i) the metal panels overlap one another and are securely attached to the wood or metal frame parts by metallic fasteners, and (ii) if the lower panel of the metallic exterior covering is secured by metallic fasteners at a cross member of the chassis by two metal straps per manufactured home unit or section at opposite ends. The bonding strap material shall be a minimum of 4 inches in width of material equivalent to the skin or a material of equal or better electrical conductivity. The straps shall be fastened with paint-penetrating fittings (such as screws and star washers or equivalent). [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55020, Oct. 25, 1993] § 3280.810 Electrical testing. (a) Dielectric strength test. (b) Additional testing. (1) An electrical continuity test to assure that metallic parts are effectively bonded; (2) An operational test of all devices and utilization equipment, except water heaters, electric ranges, electric furnaces, dishwashers, clothes washers/dryers, and portable appliances, to demonstrate they are connected and in working order; and (3) Electrical polarity checks to determine that connections have been made in accordance with applicable provisions of these standards and Article 550.17 of NFPA 70 (incorporated by reference, see § 3280.4). Visual verification is an acceptable electrical polarity check. [58 FR 55020, Oct. 25, 1993, as amended at 86 FR 2523, Jan. 12, 2021; 89 FR 75757, Sept. 16, 2024] § 3280.811 Calculations. (a) The following method shall be employed in computing the supply cord and distribution-panelboard load for each feeder assembly for each manufactured home and shall be based on a 3-wire, 120/240 volt supply with 120 volt loads balanced between the two legs of the 3-wire system. The total load for determining power supply by this method is the summation of: (1) Lighting and small appliance load as calculated below: (i) Lighting volt-amperes: Length time width of manufactured home (outside dimensions exclusive of coupler) times 3 volt-amperes per square foot; e.g. Length × width × 3 = lighting volt-amperes. (ii) Small appliance volt-amperes: Number of circuits time 1,500 volt-amperes for each 20-ampere appliance receptacle circuit (see definition of “Appliance Portable” with Note): e.g. Number of circuits × 1,500 = small appliance volt-amperes. (iii) Total volts-amperes: Lighting volts-amperes plus small appliance = total volt-amperes. (iv) First 3,000 total volts-amperes at 100 percent plus remainder at 35 percent = watts to be divided by 240 volts to obtain current (amperes) per leg. (2) Nameplate amperes for motors and heater loads (exhaust fans, air conditioners, electric, gas, or oil heating). Omit smaller of air conditioning and heating except include blower motor if used as air conditioner evaporator motor. When an air conditioner is not installed and a 40-ampere power supply cord is provided, allow 15 amperes per leg for air conditioning. (3) 25 percent of current of largest motor in paragraph (a)(2) of this section. (4) Total of nameplate amperes for: Disposal, dishwasher, water heater, clothes dryer, wall-mounted oven, cooking units. Where number of these appliances exceeds three, use 75 percent of total. (5) Derive amperes for free-standing range (as distinguished from separate ovens and cooking units) by dividing values below by 240 volts. Nameplate rating (in watts) Use (in watts) 10,000 or less 80 percent of rating. 10,001 to 12,500 8,000. 12,501 to 13,500 8,400. 13,501 to 14,500 8,800. 14,501 to 15,500 9,200. 15,501 to 16,500 9,600. 16,501 to 17,500 10,000. (6) If outlets or circuits are provided for other than factory-installed appliances, include the anticipated load. The following example is given to illustrate the application of this Method of Calculation: Example: A manufactured home is 70 × 10 feet and has two portable appliance circuits, a 1000 volt-ampere 240 volt heater, a 200 volt-ampere 120 volt exhaust fan, a 400 volts-ampere 120 volt dishwasher and a 7000 volt-ampere electric range. Lighting and small appliance load Volt-ampheres Lighting 70 × 10 × 3 2,100 Small Appliance 3,000 Total 5,100 1st. 3,000 Volt-Ampheres at 100% 3,000 Remainder (5,100 −3,000 = 2,100, at 35% 735 Total 3,735 Amperes per leg A Amperes per leg B Lighting and small Appliance 15.5 15.5 Heater 240 volt 4.1 4.1 Fan 120 volt 1.7 Dishwasher 120 volt 3.3 Range 23.3 23.3 Total 44.6 46.2 Note: Based on the higher current calculated for either leg, use one 50-A supply cord. (b) The following is an optional method of calculation for lighting and appliance loads for manufactured homes served by single 3-wire 120/240 volt set of feeder conductors with an ampacity of 100 or greater. The total load for determining the feeder ampacity may be computed in accordance with the following table instead of the method previously specified. Feeder conductors whose demand load is determined by this optional calculation are permitted to have the neutral load determined by Article 220.61 of NFPA 70 (incorporated by reference, see § 3280.4). The loads identified in the table as “other load” and as “Remainder of other load” must include the following: (1) 1500 volt-amperes for each 2-wire, 20-ampere small appliance branch circuit and each laundry branch circuit specified. (2) 3 volt-amperes per square foot for general lighting and general-use receptacles. (3) The nameplate rating of all fixed appliances, ranges, wall-mounted ovens, counter-mounted cooking units, and including 4 or more separately controlled space heating loads. (4) The nameplate ampere or kVA rating of all motors and of all low-power-factor loads. (5) The largest of the following: (i) Air conditioning load; (ii) The 65 percent diversified demand of the central electric space heating load; (iii) The 65 percent diversified demand of the load of less than four separately-controlled electric space heating units. (iv) The connected load of four or more separately-controlled electric space heating units. Optional Calculation for Manufactured Homes With 110-Ampere or Larger Service Load (in kilowatt or kilovoltampere) Demand factor Air-conditioning and cooling including heat pump compressors 100 Central electric space heating 65 Less than 4 separately controlled electric space heating units 65 1st 10 kW of all other load 100 Remainder of other load 40 [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55021, Oct. 25, 1993; 70 FR 72052, Nov. 30, 2005; 89 FR 75757, Sept. 16, 2024] § 3280.812 Wiring of expandable units and dual units. (a) Expandable or multiple unit manufactured homes shall use fixed-type wiring methods and materials for connecting such units to each other. (b) Expandable or multiple unit manufactured homes not having permanently installed feeders and which are to be moved from one location to another, shall be permitted to have disconnecting means with branch circuit protective equipment in each unit when so located that after assembly or joining together of units the requirements of § 3280.803 will be met. § 3280.813 Outdoor outlets, fixtures, air-conditioning equipment, etc. (a) Outdoor fixtures and equipment shall be listed for use in wet locations, except that if located on the underside of the home or located under roof extensions or similarly protected locations, they may be listed for use in damp locations. (b) A manufactured home provided with a branch circuit designed to energize outside heating equipment or air-conditioning equipment, other than room air conditioners, or both, located outside the manufactured home, other than room air conditioners, must have such branch-circuit conductors terminate in a listed outlet box, or disconnecting means, located on the outside of the manufactured home. (1) A label must be permanently affixed adjacent to the outlet box. The label must be not less than 0.020-inches thick etched brass, stainless steel, anodized or alclad aluminum, or equivalent, and must not be less than 3 inches × 1 3/4 (2)(i) The label must include the correct voltage and ampere rating and the following information: THIS CONNECTION IS FOR HEATING AND/OR AIR-CONDITIONING EQUIPMENT. THE BRANCH CIRCUIT IS RATED AT NOT MORE THAN____AMPERES, AT____VOLTS, 60-HERTZ,____CONDUCTOR AMPACITY. A DISCONNECTING MEANS IS LOCATED WITHIN SIGHT OF THE EQUIPMENT. (ii) The correct voltage and ampere rating shall be given. The tag must be not less than 0.020-inches thick etched brass, stainless steel, anodized or alclad aluminum, or equivalent. The tag must have a minimum size of not less than 3 inches × 1 3/4 [40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55021, Oct. 25, 1993; 78 FR 73992, Dec. 9, 2013] § 3280.814 Painting of wiring. During painting or staining of the manufactured home, it shall be permitted to paint metal raceways (except where grounding continuity would be reduced) or the sheath of the nonmetallic cable. Some arrangement, however, shall be made so that no paint shall be applied to the individual wires, as the color coding may be obliterated by the paint. § 3280.815 Polarization. (a)(1) Except as provided in paragraph (a)(2) of this section, the white conductor must be employed for the grounded (neutral) circuit conductors only and must be connected to the white terminal or lead on receptacle outlets and fixtures. The grounded conductor must be the unswitched wire in switched circuits. (2) A cable containing an insulated conductor with a white or natural gray outer finish or a marking of three continuous white stripes may be used for single-pole, three-way, or four-way switch loops, where this conductor is used for the supply to the switch, but not as a return conductor from the switch to the switched outlet. In these applications, the conductor with white or natural gray insulation or with three continuous white stripes must be permanently re-identified to indicate its use by painting or other effective means at its terminations and at each location where the conductor is visible and accessible. (b) If the identified (white) conductor of a cable is used for other than grounded conductors or for other than switch loops as explained above (for a 240 volt circuit for example), the conductor shall be finished in a color other than white at each outlet where the conductors are visible and accessible. (c) Green-colored wires or green with yellow stripe shall be used for grounding conductors only. [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55021, Oct. 25, 1993; 78 FR 73992, Dec. 9, 2013] § 3280.816 Examination of equipment for safety. The examination or inspection of equipment for safety, according to this standard, shall be conducted under uniform conditions and by organizations properly equipped and qualified for experimental testing, inspections of the run of goods at factories, and service-value determinations through field examinations. Subpart J—Transportation § 3280.901 Scope. Subpart J of this standard covers the general requirement for designing the structure of the manufactured home to fully withstand the adverse effects of transportation shock and vibration without degradation of the integrated structure or of its component parts and the specific requirements pertaining to the transportation system and its relationship to the structure. § 3280.902 Definitions. (a) Chassis (b) Drawbar and coupling mechanism (c) Frame (d) Running gear assembly (e) Lights (f) Transportation system, (g) Highway, [40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 47 FR 28093, June 29, 1982; 86 FR 2523, Jan. 12, 2021] § 3280.903 General requirements for designing the structure to withstand transportation shock and vibration. (a) General. (b) Testing or analysis requirements. (1) Road tests. (2) Engineering analysis. e.g., e.g., (i)(A) The summation of the design loads in paragraphs (b)(2)(i)(A)( 1 3 ( 1 ( 2 ( 3 (B) However, the in-transit design loading need not exceed twice the dead load of the manufactured home. (ii) To determine the adequacy of individual longitudinal structural components to resist the in-transit design loading, a load distribution based on the relative flexural rigidity and shear stiffness of each component may be utilized. For the purpose of loading distribution, the sidewall may be considered to be acting as a “deep beam” in conjunction with other load carrying elements in determining the relative stiffness of the integrated structure. Further, by proper pre-cambering of the chassis assembly, additional loading may be distributed to the chassis, and the remaining loading may be distributed to each of the load carrying members by the relative stiffness principle. (iii) The analysis is also to include consideration for: (A) Location of openings in the sidewall during transport and, when appropriate, provisions for reinforcement of the structure and/or chassis at the opening. (B) Sidewall component member sizing and joint-splice analysis ( i.e., [86 FR 2523, Jan. 12, 2021] § 3280.904 Specific requirements for designing the transportation system. (a) General. (b) Specific requirements Drawbar. (2) Coupling mechanism. (3) Chassis. (4) Running gear assembly Design criteria. (ii) Location. (5) Spring assemblies. (6) Axles. (i) Recycled axles. (ii) [Reserved]. (7) Hubs and bearings. (8) Tires, wheels, and rims. (i) Inflation pressure. (ii) Used tires. 1/16 e.g., (9) Brake assemblies Braking axles. (ii) Stopping distance. (iii) Electrical brake wiring. (10) Lamps and associated wiring. [40 FR 58752, Dec. 18, 1975, as amended at 86 FR 2524, Jan. 12, 2021] Subpart K—Attached Manufactured Homes and Special Construction Considerations Source: 86 FR 2525, Jan. 12, 2021, unless otherwise noted. § 3280.1001 Scope. This subpart covers the requirements for attached manufactured homes and other related construction associated with manufactured homes not addressed elsewhere within this part. § 3280.1002 Definitions. The following definitions are applicable to this subpart only: Attached manufactured home. i.e., Fire separation wall. § 3280.1003 Attached manufactured home unit separation. (a) Separation requirements. (2) Fire-resistance-rated floor/ceiling and wall assemblies shall extend to and be tight against the exterior wall, and wall assemblies shall extend from the foundation to the underside of the roof sheathing. (b) Fire separation penetrations. (2) Membrane penetrations for electrical boxes are permitted on the living side of the wall under the following conditions: (i) Steel electrical boxes not exceeding 16 square inches may be installed provided that the total area of such boxes does not exceed 100 square inches in any 100 square feet wall area. Steel electrical boxes in adjacent fire separation walls must be separated by a horizontal distance of not less than 24 inches. (ii) Listed 2-hour fire-resistant nonmetallic electrical boxes are installed in accordance with the listings. (iii) No other membrane penetrations are allowed. (c) Continuity of walls. (d) Parapets. (i) Where roof surfaces adjacent to the fire separation walls are at the same elevation, the parapet must extend not less than 30 inches above the roof surfaces. (ii) Where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is not more than 30 inches above the lower roof surface, the parapet must not extend less than 30 inches above the lower roof surface. (A) Parapets must be provided unless roofs are of a Class C roof covering and the roof decking or sheathing is of noncombustible materials or approved fire-retardant-treated wood for a distance of four feet on each side of the common fire separation walls; or one layer of 5/8 (B) A parapet must not be required where roof surfaces adjacent to the common walls are at different elevations and the higher roof is more than 30 inches above the lower roof. The fire separation wall construction from the lower roof to the underside of the higher roof deck must not have less than a 1-hour fire-resistive rating. The wall must be rated for exposure from both sides. (2) Parapets must have the same fire resistance rating as that required for the supporting wall or walls. On any side adjacent to a roof surface, the parapet must have noncombustible faces for the uppermost 18 inches, to include counter flashing and coping materials. Where the roof slopes toward a parapet at slopes greater than 2/12 [86 FR 2525, Jan. 12, 2021, as amended at 89 FR 75757, Sept. 16, 2024] § 3280.1004 Exterior walls. (a) The requirements of § 3280.504 for condensation control and vapor retarder installation are required to be provided on each fire separation wall of each attached manufactured home. (b) The requirements of § 3280.506 for heat loss/gain insulation apply to the fire separation wall on each attached manufactured home. § 3280.1005 Electrical service. (a) Each attached manufactured home must be supplied by only one service. (b) Service conductors supplying one manufactured home must not pass through the interior of another manufactured home. § 3280.1006 Water service. (a) Each manufactured home must have an individual water supply that will service only that unit. (b) Each manufactured home must have a hot water supply system that will service only that unit.

24 CFR Part 3280 — Manufactured Home Construction and Safety Standards

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