California Code of Regulations › Title 25 - Housing and Community Development › Division 1 - Housing and Community Development › Chapter 3 - Factory-Built Housing, Mobilehomes, and Manufactured Homes › Subchapter 2 - Manufactured Homes, Mobilehomes, Multifamily Manufactured Homes, Commercial Modulars, and Special Purpose Commercial Modulars › Article 1.1 - Issuance of Insignia for Manufactured Homes, Mobilehomes and Commercial Coaches Not Previously Issued Insignia of Approval › Section 4049.3 - Structural, Fire Safety and Energy Requirements

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) In lieu of the requirements of Section
					 4050(b), the structural, fire safety and energy equipment and installations of
					 manufactured homes and mobile homes manufactured on or after September 15,
					 1971, and before June 15, 1976, shall conform to the following:
(1) Minimum Requirements. The design and
					 construction of a manufactured home or mobile home shall conform with the
					 provisions of this article. Requirements for any size, weight, or quality of
					 material modified by the terms of "minimum," "not less than," "at least," and
					 similar expressions are minimum standards.
(2) Construction. All construction methods
					 shall be in conformance with accepted engineering practice standards to ensure
					 durable, livable, and safe housing. Exposed metal structural members shall be
					 protected to resist corrosion.
(3)
					 Structural Analysis. The strength and rigidity of the component parts and/or
					 the integrated structure shall be determined by engineering analysis.
(4) Design Dead Loads. Design dead loads
					 shall be actual dead load supported by the structural assembly under
					 consideration.
(5) Design Live
					 Loads. The design live loads shall be as specified in Sections 4049.3 (a)(6),
					 (7), (8), (10), (13), (16) and (17) and shall be considered to be uniformly
					 distributed. The roof live load shall not be considered as acting
					 simultaneously with the wind load and the roof and floor live loads shall not
					 be considered as resisting the overturning moment due to wind.
(6) Wind Loads. Manufactured homes or mobile
					 homes shall be designed to withstand minimum horizontal and uplift pressures
					 from any direction as follows:
Horizontal....................
...................15 lb/ft2
Vertical (horizontal
								projection)...........................
....................9
								lb/ft2 uplift
Unit stresses may be increased in accordance with the
						applicable accepted engineering practice standards.
(7) Roof Loads. Flat, curved and pitched roof
					 members shall be designed to sustain all loadings as follows:
(A) All dead loads plus a minimum unit live
					 load of 20 lb/ft2
(B) A vertical uplift load of 9
					 lb/ft2
(8) Snow Loads. Where it is known that the
					 manufactured home or mobile home will be subjected to snow loads, the
					 manufactured home or mobile home shall be designed for the appropriate loads.
					 Unit stresses may be increased in accordance with applicable accepted
					 engineering practice standards.
(9)
					 Fastening of Structural Systems. Roof framing shall be securely fastened to
					 wall framing, walls to floor structure, and floor structure to chassis to
					 secure and maintain continuity between the floor and chassis, so as to resist
					 wind overturning and sliding as imposed by design loads in Section
					 4049.3(a)(6).
(10) Walls. The walls
					 shall be of sufficient strength to withstand the load requirements as defined
					 in Section 4049.3(a)(6), (7) and (8) and without exceeding the deflections
					 specified in Section 4049.3(a)(16). The connections between the bearing walls,
					 floor, and roof framework members shall be fabricated in such a manner as to
					 provide support for the material used to enclose the manufactured home or
					 mobile home and to provide for transfer of all lateral and vertical loads to
					 the floor and chassis.
(11)
					 Interior Walls. Interior walls 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.
(12) Firestopping. Firestopping shall be
					 provided in multistory manufactured homes or mobile homes to cut off all
					 concealed draft openings in all stud walls and partitions, including furred
					 spaces, so placed that the maximum vertical dimension of any concealed space is
					 not over eight feet.
(13) Floors.
(A) Floor assemblies shall be designed in
					 accordance with accepted engineering practice standards to support a minimum
					 uniform live load of 40 lb/ft2 plus the dead load of
					 the materials. In addition (but not simultaneously), floors shall be able to
					 support a 200-pound concentrated load on a two inch diameter disc at the most
					 critical location with a maximum deflection not to exceed one-eighth inch
					 relative to floor framing. Perimeter joists of more than six inches depth shall
					 be stabilized against overturning from superimposed loads as follows: at ends
					 by solid blocking not less than two inch thickness by full depth of joist, or
					 by connecting to a continuous header not less than two inch thickness and not
					 less than the depth of the joist with connecting device; at eight feet maximum
					 intermediate spacing by solid blocking or by wood cross-bridging of not less
					 than one inch by three inches, metal cross-bridging of equal strength, or by
					 other approved methods.
(B) Wood
					 floors or subfloors in kitchen, bathrooms (including toilet compartments),
					 laundry rooms, 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.
(14) Carpet. Carpet and/or carpet pads shall
					 not be installed in concealed spaces subject to excessive moisture such as
					 under plumbing fixtures. Carpet and/or pads shall not be installed beneath the
					 bottom plate of shear and bearing walls.
(15) Underfloor Closure Material. Underfloor
					 closure material and method of construction shall be such as to resist damage
					 which would permit penetration of the underside of the manufactured home or
					 mobile home by water, rodents or insects.
(16) Deflections. Deflection of structural
					 assemblies shall not exceed the following:
Floor.........................
...................L/240
Roof and Ceiling
								Members..................
...................L/180
Sidewalls.......................
...................L/180
Where L = the clear span between supports or two times
						the length of a cantilever.
(17) Roof Members. Roof members shall be
					 capable of withstanding the loads and meet the deflection requirements of
					 Sections 4049.3(a)(6), (7), (8), and (16).
(18) Roof Coverings.
(A) General. Roof coverings shall be securely
					 fastened in an approved manner to the supporting roof construction and shall
					 provide weather protection for the manufactured home or mobile home and the
					 occupants. All roof decks shall be designed with sufficient slope or camber to
					 assure adequate drainage, or shall be designed to support maximum loads
					 including possible ponding of water due to deflection. Roof covering shall be
					 installed pursuant to the manufacturer's instructions and as approved by the
					 department.
(B) Construction. All
					 roofs shall be so framed and tied into the framework and supporting walls as to
					 form an integral part of the manufactured home or mobile home. All trusses
					 shall be laterally braced.
(19) Weather Resistance. Exterior covering
					 shall be of moisture and weather resistive materials attached with corrosion
					 resistant fasteners to resist wind and rain. Metal coverings shall be of
					 corrosion resistant materials.
(20)
					 Rodent Resistance. Exterior surfaces shall be sealed to resist the entrance of
					 rodents.
(21) Heat Loss. The total
					 calculated heat loss of the living unit at the outdoor design temperature shall
					 not exceed 40 Btu/hr/ft2 of the total floor area or
					 275 Btu/hr lineal ft. of the perimeter of the space to be heated to 70° F,
					 whichever is greater. The minimum total resistance value (R), excluding
					 framing, of the wall (less windows and doors), ceiling, and floor shall not be
					 less than:
Wall..................................
..................................8.0
Ceiling...................................
..................................16.0
Floor...................................
..................................10.0
(22) "R" values and "U" factors shall be
					 calculated in accord with the provisions of Chapter 20 of the 1972 ASHRAE
					 Handbook of Fundamentals (American Society of Heating, Refrigerating, and Air
					 Conditioning Engineers, 345 East 74th Street, New York, New York
					 10017).
(23) Framing Heat Loss. In
					 the absence of specific data, for the purpose of heat loss calculations, the
					 following framing areas shall be assumed:
Wall...................................
..................................20% of net wall area (less windows)
Ceiling...................................
..................................5% of total ceiling area
Floor...................................
..................................10% of net floor area (less duct area)
(24) Infiltration Heat Loss. The following
					 shall be used to estimate infiltration heat loss, or infiltration heat loss may
					 be calculated using the method in Chapter 19 of the 1972 ASHRAE Handbook of
					 Fundamentals (American Society of Heating, Refrigerating, and Air Conditioning
					 Engineers, 345 East 74th Street, New York, New York 10017).
Outside Design Temperature
								Degrees F
Infiltration Allowance
								Btu/hr
40..........................
..........................3,330
30..........................
..........................4,440
20..........................
..........................5,550
10..........................
..........................6,660
0..........................
..........................7,770
minus
10..........................
..........................8,880
minus
20..........................
..........................9,990
minus
30..........................
..........................11,100
minus
40..........................
..........................12,210
(25) Light and Ventilation. Adequate
					 provisions shall be made for light and ventilation in accordance with the
					 following:
(A) Habitable Rooms. Habitable
					 rooms shall be provided with exterior windows or doors having a total glazed
					 area of not less than 10 percent of the gross floor area. An area equivalent to
					 not less than 5 percent of the gross floor area shall be available for
					 unobstructed ventilation. Glazed areas need not be openable where a mechanical
					 ventilation system is provided and is capable of producing a change of air in
					 the room(s) every thirty minutes with not less than one-fifth of the air supply
					 taken from outside the manufactured home or mobile home. However, kitchens may
					 be provided with artificial light and mechanical ventilation capable of
					 producing a change of air in the room every 30 minutes. Windows and doors used
					 for light or ventilation shall open directly to the outside of the manufactured
					 home or mobile home.
(B) Bathroom.
					 Each bathroom shall be provided with artificial light and, in addition, be
					 provided with external windows or doors having not less than 1-1/2 square feet
					 of fully openable glazed area, except where a mechanical ventilation system is
					 provided capable of producing a change of air every 12 minutes. Any mechanical
					 ventilation system shall exhaust directly to the outside of the manufactured
					 home or mobile home.
(26)
					 Ceiling Height. Every habitable room shall have a minimum ceiling height of not
					 less than seven feet in at least 50 percent of its required area with no
					 portion of the required area less than five feet in height. Hallways shall have
					 a minimum ceiling height of six feet, six inches.
(27) Exit Facilities.
(A) Manufactured homes or mobile homes shall
					 have a minimum of two exterior doors located remote from each other and so
					 arranged as to provide a means of unobstructed travel to the outside of the
					 manufactured home or mobile home.
(B) Exterior doors shall be constructed for
					 exterior use and in no case provide less than a 28-inch-wide clear opening.
					 Each exterior door shall have a key-operated lock. The locking mechanism of the
					 lock shall be engaged or disengaged by the use of a lever, knob, button,
					 handle, or other device from the inside. Locks shall not require the use of a
					 key for operation from the inside.
(C) Every room designed expressly for
					 sleeping purposes, unless it has an exit door (see Section 4049.3(a)(27)(B)),
					 shall have at least one outside window which can be opened from the inside
					 without the use of tools to provide a clear opening of not less than 22 inches
					 in least dimension and five square feet in area with the bottom of the opening
					 not more than four feet above the floor. Where a screen or storm window must be
					 removed from this window to permit emergency egress, it shall be readily
					 removable without requiring the use of tools.
(28) Interior Passage. 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.
(29) Every
					 manufactured home or mobile home shall have at least one habitable room with
					 not less than 150 square feet of gross floor area. Rooms designed for sleeping
					 purposes shall have a minimum gross square foot floor area as follows:
One person..............................
..............................50
Two
								persons...............................
..............................70
Each person in excess of
								two...............................
..............................50
(30) No habitable room, except a kitchen,
					 shall be less than five feet in any clear horizontal dimension.
(31) Hallways shall have a minimum horizontal
					 dimension of 28 inches.
(32)
					 Glazing in hazardous locations shall comply with Table MH-1. Table MH-1 Glazing
					 in the Following Specific Hazardous Locations Shall Meet the Following
					 Requirements
Specific Hazardous
								  Locations
Size of Individual
								  Glazed Area
Requirements 
								  2
Glazing in exit and entrance
								doors..........................
Over 6 sq. ft.
Each glazed area
								shall pass
the requirements of ANSI
								Standard Z97.1 
								3 if not protected by a
								protective grille 
								1 firmly attached to stiles
								on each exposed side.
Glazing in storm
								doors..........................
Over 2 sq. ft.
Each glazed area
								shall pass
the requirements of ANSI
								Standard Z97.1 
								3 if not protected by a
								protective grille 
								1 firmly attached to stiles
								on each exposed side.
Glazing in sliding exterior
								doors..........................
All Sizes
Each glazed area
								shall pass
the requirements of ANSI
								Standard Z97.1.3
Glazing in all unframed doors
								(swinging)..........................
All Sizes
Each glazed area
								shall be
fully tempered glass and pass
								the requirements of ANSI Standard Z97.1.3
Glazing in shower doors and tub
								enclosures..........................
All Sizes
Each glazed area
								shall pass
the test requirements of ANSI
								Standard Z97.1.3
Other fixed glazed panels located within 12 inches
								on either side of exit and entrance doors..........................
All
								Sizes
Each glazed area within 18
inches of the floor shall pass
								the requirements of ANSI Standard Z97.1 
								3 unless the glazed area is
								protected by a barrier within 12 inches immediately in front of the
								glazing.
1 Shall be constructed and
						attached in such a manner so as to prevent human impact from being delivered to
						glass surface.
2 Annealed glass less than
						single strength (SS) in thickness shall not be used. If short dimension is
						larger than 24 inches, annealed glass must be double strength (DS) or
						thicker.
3 American National Standard
						Performance Specifications and Methods of Test for Safety Glazing Material Used
						in Buildings, as approved January 20, 1972, American National Standards
						Institute, 1430 Broadway, New York, New York 10018.
(33) Fire Warning Equipment. At least one
					 listed smoke detector (which may be a single station alarm device) shall be
					 installed in each manufactured home or mobile home.
For the purpose of this article, a "smoke detector" is a
						device which detects visible or invisible particles of combustion. A "single
						station alarm device" is an assembly incorporating a detector and an alarm
						sounding device in one unit, operated from a power supply either in the unit or
						obtained at the point of installation. Detectors shall operate from an AC,
						monitored battery, or combination AC/battery power source.
(34) Smoke Detector Location. Smoke
					 detector(s) shall be located outside of bedrooms or in a hallway or space
					 communicating thereto, on or near the ceiling, and shall be installed in
					 accordance with the manufacturer's instructions. Manufactured homes or mobile
					 homes having bedrooms separated by any one or a combination of common use
					 areas, such as a kitchen, dining room, living room, or family room (but not a
					 bathroom or utility room), shall have at least two detectors.
(35) Alarm Sounding Device. Every
					 smoke-detector shall have an operable alarm signaling device or devices which
					 is clearly audible in all bedrooms with all intervening doors closed and is
					 rated not less than 85 decibels at 10 feet.
(36) Detector Trouble Signals. Detectors
					 requiring a light source for operation shall have an audible trouble signal on
					 failure of the light source, but such failure shall not cause an alarm.
					 Detectors not requiring a light source for operation shall have either a
					 visible light to indicate operability or an audible trouble signal. Audible
					 trouble signals shall be designed to operate at least every minute for seven
					 consecutive days.