What requirements apply to acoustical ceiling systems and plenum installations?

Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:

• CBC § 803.1.2. High relevance — show source text

  Exception: Lockers constructed entirely of wood and noncombustible materials shall be permitted to be used wherever interior finish materials are required to meet a Class C classification in accordance with Section 803.1.2.

  SECTION 807—INSULATION

  807.1 Insulation. Thermal and acoustical insulation shall comply with Section 720.

  SECTION 808—ACOUSTICAL CEILING SYSTEMS

  808.1 Acoustical ceiling systems. The quality, design, fabrication and erection of metal suspension systems for acoustical tile and lay-in panel ceilings in buildings or structures shall conform to generally accepted engineering practice, the provisions of this chapter and other applicable requirements of this code.

  808.1.1 Materials and installation. Acoustical materials complying with the interior finish requirements of Section 803 shall be installed in accordance with the manufacturer’s recommendations and applicable provisions for applying interior finish.

  808.1.1.1 Suspended acoustical ceilings. Suspended acoustical ceiling systems shall be installed in accordance with the provisions of ASTM C635 and ASTM C636.

  808.1.1.2 Fire-resistance-rated construction. Acoustical ceiling systems that are part of fire-resistance-rated construction shall be installed in the same manner used in the assembly tested and shall comply with the provisions of Chapter 7.

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  CALIFORNIA BUILDING CODE – MATRIX ADOPTION TABLE

  CHAPTER 9 – FIRE PROTECTION AND LIFE SAFETY SYSTEMS

  (Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

  Adopting agency	BSC	BSC- CG	SFM	HCD	Col6	Col7	DSA	Col9	Col10	OSHPD	Col12	Col13	Col14	Col15	Col16	Col17	BSCC	DPH	AGR	DWR	CEC	CA	SL	SLC
  Adopting agency	BSC	BSC- CG	SFM	1	2	1/AC	AC	SS	SS/CC	1	1R	2	3	4	5	6	6	6	6	6	6	6	6	6
  Adopt entire chapter	X							X	X	X	X	X	X	X	X	X
  Adopt entire chapter as amended (amended sections listed below)			X	X	X
  Adopt only those sections that are listed below						X	X																X
  Chapter / Section
  901.5			X
  903.

• CBC § 806.6. High relevance — show source text

  Exception: Interior trim materials that comply with Section 806.6.

  [F] 806.8 Combustible lockers. Where lockers constructed of combustible materials are used, the lockers shall be considered to be interior finish and shall comply with Section 803.

  Exception: Lockers constructed entirely of wood and noncombustible materials shall be permitted to be used wherever interior finish materials are required to meet a Class C classification in accordance with Section 803.1.2.

  SECTION 807—INSULATION

  807.1 Insulation. Thermal and acoustical insulation shall comply with Section 720.

  SECTION 808—ACOUSTICAL CEILING SYSTEMS

  808.1 Acoustical ceiling systems. The quality, design, fabrication and erection of metal suspension systems for acoustical tile and lay-in panel ceilings in buildings or structures shall conform to generally accepted engineering practice, the provisions of this chapter and other applicable requirements of this code.

  808.1.1 Materials and installation. Acoustical materials complying with the interior finish requirements of Section 803 shall be installed in accordance with the manufacturer’s recommendations and applicable provisions for applying interior finish.

  808.1.1.1 Suspended acoustical ceilings. Suspended acoustical ceiling systems shall be installed in accordance with the provisions of ASTM C635 and ASTM C636.

  808.1.1.2 Fire-resistance-rated construction. Acoustical ceiling systems that are part of fire-resistance-rated construction shall be installed in the same manner used in the assembly tested and shall comply with the provisions of Chapter 7.

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  CALIFORNIA BUILDING CODE – MATRIX ADOPTION TABLE

  CHAPTER 9 – FIRE PROTECTION AND LIFE SAFETY SYSTEMS

  (Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

• CBC § 806.4 High relevance — show source text

  [F] 806.4 Acceptance criteria and reports. Where required to exhibit improved fire performance, curtains, draperies, fabric hangings and similar combustible decorative materials suspended from walls or ceilings shall be tested by an approved agency and shall be flame resistant in accordance with the provisions set forth in CCR, Title 19, Division 1, Chapter 8 . Reports of test results shall be prepared in accordance with the test method used and furnished to the building official on request.

  2025 CALIFORNIA BUILDING CODE 8-7

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  INTERIOR FINISHES

  [F] 806.5 Pyroxylin plastic. Imitation leather or other material consisting of or coated with a pyroxylin or similarly hazardous base shall not be used in Group A occupancies.

  [F] 806.6 Interior trim. Material, other than foam plastic used as interior trim, shall have a minimum Class B flame spread and 450 smoke-developed index in Group I-3 and for all other occupancies Class C flame spread and smoke-developed index when tested in accordance with ASTM E84 or UL 723, as described in Section 803.1.2. Combustible trim, excluding handrails and guardrails, shall not exceed 10 percent of the specific wall or ceiling area to which it is attached.

  [F] 806.6.1 Foam plastic. Foam plastic used as interior trim in any occupancy shall comply with Section 2604.2.

  [F] 806.7 Interior floor-wall base. Interior floor-wall base that is 6 inches (152 mm) or less in height shall be tested in accordance with Section 804.2 and shall be not less than Class II. Where a Class I floor finish is required, the floor-wall base shall be Class I.

  Exception: Interior trim materials that comply with Section 806.6.

  [F] 806.8 Combustible lockers. Where lockers constructed of combustible materials are used, the lockers shall be considered to be interior finish and shall comply with Section 803.

  Exception: Lockers constructed entirely of wood and noncombustible materials shall be permitted to be used wherever interior finish materials are required to meet a Class C classification in accordance with Section 803.1.2.

  SECTION 807—INSULATION

  807.1 Insulation. Thermal and acoustical insulation shall comply with Section 720.

  SECTION 808—ACOUSTICAL CEILING SYSTEMS

  808.1 Acoustical ceiling systems. The quality, design, fabrication and erection of metal suspension systems for acoustical tile and lay-in panel ceilings in buildings or structures shall conform to generally accepted engineering practice, the provisions of this chapter and other applicable requirements of this code.

  808.1.1 Materials and installation. Acoustical materials complying with the interior finish requirements of Section 803 shall be installed in accordance with the manufacturer’s recommendations and applicable provisions for applying interior finish.

  808.1.1.1 Suspended acoustical ceilings. Suspended acoustical ceiling systems shall be installed in accordance with the provisions of ASTM C635 and ASTM C636.

  808.1.1.2 Fire-resistance-rated construction. Acoustical ceiling systems that are part of fire-resistance-rated construction shall be installed in the same manner used in the assembly tested and shall comply with the provisions of Chapter 7.

• CBC § 2603.4. High relevance — show source text

  Exceptions:

  1. Foam plastic in plenums used as interior wall or ceiling finish, or interior trim, shall exhibit a flame spread index of 75 or less and a smoke-developed index of 450 or less when tested in accordance with ASTM E84 or UL 723 at the maximum thickness and density intended for use, where it is separated from the airflow in the plenum by a thermal barrier complying with Section 2603.4.
  2. Foam plastic in plenums used as interior wall or ceiling finish, or interior trim, shall exhibit a flame spread index of 75 or less and a smoke-developed index of 450 or less when tested in accordance with ASTM E84 or UL 723 at the maximum thickness and density intended for use, where it is separated from the airflow in the plenum by corrosion-resistant steel having a base metal thickness of not less than 0.0160 inch (0.4 mm).
  3. Foam plastic in plenums used as interior wall or ceiling finish, or interior trim, shall exhibit a flame spread index of 75 or less and a smoke-developed index of 450 or less when tested in accordance with ASTM E84 or UL 723 at the maximum thickness and density intended for use, where it is separated from the airflow in the plenum by not less than a 1-inch (25 mm) thickness of masonry or concrete.

  2603.8 Protection against termites. In areas where the probability of termite infestation is very heavy in accordance with Figure 2603.8, extruded and expanded polystyrene, polyisocyanurate and other foam plastics shall not be installed on the exterior face or under interior or exterior foundation walls or slab foundations located below grade. The clearance between foam plastics installed above grade and exposed earth shall be not less than 6 inches (152 mm).

  Exceptions:

  1. Buildings where the structural members of walls, floors, ceilings and roofs are entirely of noncombustible materials or preservative-treated wood.

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  PLASTIC

  2. An approved method of protecting the foam plastic and structure from subterranean termite damage is provided.

  3. On the interior side of basement walls.

  FIGURE 2603.8—TERMITE INFESTATION PROBABILITY MAP

  2603.9 Special approval. Foam plastic shall not be required to comply with the requirements of Section 2603.4 or those of Section 2603.6 where specifically approved based on one of the following large-scale tests:

  1. NFPA 286 using the acceptance criteria of Section 803.1.1.1.

  2. FM 4880.

  3. UL 1040.

  4. UL 1715.

  Such testing shall be performed on the finished manufactured foam plastic assembly in the maximum thickness intended for use. Foam plastics that are used as interior finish on the basis of these tests shall also conform to the flame spread and smoke-developed requirements of Chapter 8. Assemblies tested shall include seams, joints and other typical details used in the installation of the assembly and shall be tested in the manner intended for use.

  [BS] 2603.10 Wind resistance. Foam plastic insulation complying with ASTM C578 and ASTM C1289 and used as exterior wall sheathing on framed wall assemblies shall comply with ANSI/SBCA FS 100 for wind pressure resistance.

  SECTION 2604—INTERIOR FINISH AND TRIM

• CBC § 5.507.4.2 High relevance — show source text

  5.507.4.2 Performance method. For buildings located as defined in Section 5.507.4.1 or 5.507.4.1.1, wall and roof-ceiling assemblies exposed to the noise source making up the building or addition envelope or altered envelope shall be constructed to provide an interior noise environment attributable to exterior sources that does not exceed an hourly equivalent noise level ( L eq - 1Hr) of 50 dBA in occupied areas during any hour of operation.

  5.507.4.2.1 Site features. Exterior features such as sound walls or earth berms may be utilized as appropriate to the building, addition or alteration project to mitigate sound migration to the interior.

  5.507.4.2.2 Documentation of compliance. An acoustical analysis documenting complying interior sound levels shall be prepared by personnel approved by the architect or engineer of record.

  5.507.4.3 Interior sound transmission. Wall and floor- ceiling assemblies separating tenant spaces and tenant spaces and public places shall have an STC of at least 40.

  Note: Examples of assemblies and their various STC ratings may be found at the [California Office of Noise Control:](http://www.toolbase.org/PDF/CaseStudies/ stc_icc_ratings.pdf) http://www.toolbase.org/PDF/CaseStudies/ stc_icc_ratings.pdf.

  SECTION 5.508

  OUTDOOR AIR QUALITY

  5.508.1 Ozone depletion and greenhouse gas reductions. Installations of HVAC, refrigeration and fire suppression equipment shall comply with Sections 5.508.1.1 and 5.508.1.2.

  5.508.1.1 Chlorofluorocarbons (CFCs). Install HVAC, refrigeration and fire suppression equipment that do not contain CFCs.

  5.508.1.2 Halons. Install HVAC, refrigeration and fire suppression equipment that do not contain Halons.

  5.508.2 Supermarket refrigerant leak reduction. New commercial refrigeration systems shall comply with the provisions of this section when installed in retail food stores 8,000 square feet or more conditioned area, and that utilize either refrigerated display cases, or walk-in coolers or freezers connected to remote compressor units or condensing units. The leak reduction measures apply to refrigeration systems containing high-global-warming potential (high-GWP) refrigerants with a GWP of 150 or greater. New refrigeration systems include both new facilities and the replacement of existing refrigeration systems in existing facilities.

  Exception: Refrigeration systems containing low-global warming potential (low-GWP) refrigerant with a GWP value less than 150 are not subject to this section. Low-GWP refrigerants are nonozone-depleting refrigerants that include ammonia, carbon dioxide (CO 2 ), and potentially other refrigerants.

  5.508.2.1 Refrigerant piping. Piping compliant with the California Mechanical Code shall be installed to be accessible for leak protection and repairs. Piping runs using threaded pipe, copper tubing with an outside diameter (OD) less than [1] / 4 inch, flared tubing connections and short radius elbows shall not be used in refrigerant systems except as noted below.

  5.508.2.1.1 Threaded pipe. Threaded connections are permitted at the compressor rack. 5.508.2.1.2 Copper pipe. Copper tubing with an OD less than [1] / 4 inch may be used in systems with a refrigerant charge of 5 pounds or less.

• CBC § 2603.5.7 High relevance — show source text

  2603.5.7 Ignition. Exterior walls shall not exhibit sustained flaming where tested in accordance with NFPA 268. Where a material is intended to be installed in more than one thickness, tests of the minimum and maximum thickness intended for use shall be performed.

  Exception: Assemblies protected on the outside with one of the following:

  1. A thermal barrier complying with Section 2603.4.
  2. A minimum 1-inch (25 mm) thickness of concrete or masonry.
  3. Glass-fiber-reinforced concrete panels of a minimum thickness of [3] / 8 inch (9.5 mm).
  4. Metal-faced panels having minimum 0.019-inch-thick (0.48 mm) aluminum or 0.016-inch-thick (0.41 mm) corrosionresistant steel outer facings.
  5. A minimum [7] / 8 -inch (22.2 mm) thickness of stucco complying with Section 2510.
  6. A minimum [1] / 4 -inch (6.4 mm) thickness of fiber-cement lap, panel or shingle siding complying with Section 1404.17 and Section 1404.17.1 or 1404.17.2.

  2603.6 Roofing. Foam plastic insulation meeting the requirements of Sections 2603.2, 2603.3 and 2603.4 shall be permitted as part of a roof-covering assembly, provided that the assembly with the foam plastic insulation is a Class A, B or C roofing assembly where tested in accordance with ASTM E108 or UL 790.

  2603.7 Foam plastic in plenums as interior finish or interior trim. Foam plastic in plenums used as interior wall or ceiling finish, or interior trim, shall exhibit a flame spread index of 25 or less and a smoke-developed index of 50 or less when tested in accordance with ASTM E84 or UL 723 at the maximum thickness and density intended for use, and shall be tested in accordance with NFPA 286 and meet the acceptance criteria of Section 803.1.1. As an alternative to testing to NFPA 286, the foam plastic shall be approved based on tests conducted in accordance with Section 2603.9.

  Exceptions:

  1. Foam plastic in plenums used as interior wall or ceiling finish, or interior trim, shall exhibit a flame spread index of 75 or less and a smoke-developed index of 450 or less when tested in accordance with ASTM E84 or UL 723 at the maximum thickness and density intended for use, where it is separated from the airflow in the plenum by a thermal barrier complying with Section 2603.4.
  2. Foam plastic in plenums used as interior wall or ceiling finish, or interior trim, shall exhibit a flame spread index of 75 or less and a smoke-developed index of 450 or less when tested in accordance with ASTM E84 or UL 723 at the maximum thickness and density intended for use, where it is separated from the airflow in the plenum by corrosion-resistant steel having a base metal thickness of not less than 0.0160 inch (0.4 mm).
  3. Foam plastic in plenums used as interior wall or ceiling finish, or interior trim, shall exhibit a flame spread index of 75 or less and a smoke-developed index of 450 or less when tested in accordance with ASTM E84 or UL 723 at the maximum thickness and density intended for use, where it is separated from the airflow in the plenum by not less than a 1-inch (25 mm) thickness of masonry or concrete.
• CBC § 606.10 High relevance — show source text

  operation or maintenance of external operating devices needed for the function of the damper.

  606.10 Temperature Classification of Operating Ele- ments. Fusible links, thermal sensors, and pneumatic or electric operators shall have a temperature rating or classification as in accordance with the building code.

  607.0 Ventilating Ceilings.

  607.1 General. Perforated ceilings shall be permitted to be used for air supply within the limitations of this section. Exit corridors, where required to be of fire-resistive construction by the California Building Code, shall not have ventilating ceilings.

  607.1.1 [OSHPD 1, 1R, 2, 3, 4 & 5] Ventilating ceil- ings are not permitted in health facilities.

  607.2 Requirements. Ventilating ceilings shall comply with the following:

  (1) Suspended ventilating ceiling material shall have a Class 1 flame spread classification on both sides, determined in accordance with the building code. Suspended ventilating ceiling supports shall be of noncombustible materials.

  (2) Luminaires recessed into ventilating ceilings shall be of a type approved for that purpose.

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  142 2025 CALIFORNIA MECHANICAL CODE

  ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

  DUCT SYSTEMS

  608.0 Use of Under-Floor Space as Supply Plenum for Dwelling Units.

  608.1 General. An under-floor space shall be permitted to be used as a supply plenum.

  608.2 Dwelling Units. The use of under-floor space shall be limited to dwelling units not more than two stories in height. Except for the floor immediately above the underfloor plenum, supply ducts shall be provided extending from the plenum to registers on other floor levels.

  Exception: In flood hazard areas, under-floor spaces shall not be used as supply plenums unless the flood opening requirements in the building code are met.

  608.3 Enclosed. Such spaces shall be cleaned of all loose combustible scrap material and shall be tightly enclosed.

  608.4 Flammable Materials. The enclosing material of the under-floor space, including the sidewall insulation, shall be not more flammable than 1 inch (25.4 mm) (nominal) wood boards (flame-spread index of 200). Installation of foam plastics is regulated by the building code.

  608.5 Access. Access shall be through an opening in the floor and shall be not less than 24 inches by 24 inches (610 mm by 610 mm).

  608.6 Automatic Control. A furnace supplying warm air to under-floor space shall be equipped with an automatic control that will start the air-circulating fan where the air in the furnace bonnet reaches a temperature not exceeding 150°F (66°C). Such control shall be one that cannot be set to exceed 150°F (66°C).

  608.7 Temperature Limit. A furnace supplying warm air to such space shall be equipped with an approved temperature limit control that will limit outlet air temperature to 200°F (93°C).

• CBC § 12-8 High relevance — show source text

  Note: See Figure 12-8-3. C. Locations for room. Thermocouples shall be located 4 inches (101 mm) down from the center of the ceiling and from the center of each of the four ceiling quadrants, and one shall be directly over the center of the ignition burner, 4 inches (101 mm) below the ceiling. The thermocouples shall be mounted on supports, with their junctions at least 4 inches (101 mm) away from a solid surface. There shall be no attachments to the test specimens.

  Note: See Figure 12-8-3. D. Location in canopy hood and duct systems. One pair of thermocouples shall be placed 11 feet (3353 mm) downstream to the entrance to the horizontal duct. The pair of thermocouples shall straddle the center of the duct and be separated by 2 inches (51 mm) from each other.

  Note: See Figure 12-8-4. 3. Canopy hood and exhaust duct location and design. A hood shall be installed immediately adjacent to the door of the fire room. The bottom of the hood shall be level with the top surface of the room. The face dimensions of the hood shall

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  FIRE-RESISTIVE STANDARDS FOR FIRE PROTECTION

  be minimum 8 feet by 8 feet (2438 mm by 2438 mm) and the depth shall be 3.5 feet (1067 mm). The hood shall feed into a plenum having a 3-foot by 3-foot (914 mm by 914 mm) cross section.

  Note: See Figure 12-8-4. The plenum shall have a minimum height of 3 feet (914 mm). The height can be increased up to a maximum of 6 feet (1829 mm) to satisfy building constraints. The exhaust duct connected to the plenum shall be 16 inches (406 mm) in diameter, horizontal, and shall have a circular aperture of 12 inches (305 mm) at its entrance. The hood shall have sufficient draft to collect all the combustion products leaving the room. This draft should be capable of moving up to 5,000 standard cubic feet per minute (scfm) during the test. Provisions shall be made to vary the draft so that it can operate at either 1,000 or 5,000 scfm. Mixing vanes may also be required in the duct if concentration gradients are found to exist.

  An alternate exhaust system design may be used if it has been shown to produce equivalent results. Equivalency may be shown by meeting the requirements of Section 12-8-113, Item 5. 4. Duct gas velocity specification. A bidirectional probe or equivalent measuring system shall be used to measure gas velocity in the duct.

• CBC § 720.2 High relevance — show source text

  720.2 Concealed installation. Insulating materials, where concealed as installed in buildings of any type of construction, shall have a flame spread index of not more than 25 and a smoke-developed index of not more than 450.

  Exception: Cellulosic fiber loose-fill insulation complying with the requirements of Section 720.6 shall not be required to meet a flame spread index requirement but shall be required to meet a smoke-developed index of not more than 450 when tested in accordance with CAN/ULC S102.2.

  720.2.1 Facings. Where such materials are installed in concealed spaces in buildings of Type III, IV or V construction, the flame spread and smoke-developed limitations do not apply to facings, coverings, and layers of reflective foil insulation that are installed behind and in substantial contact with the unexposed surface of the ceiling, wall or floor finish.

  Exception: All layers of single and multilayer reflective plastic core insulation shall comply with Section 2614.

  720.3 Exposed installation. Insulating materials, where exposed as installed in buildings of any type of construction, shall have a flame spread index of not more than 25 and a smoke-developed index of not more than 450.

  Exception: Cellulosic fiber loose-fill insulation complying with the requirements of Section 720.6 shall not be required to meet a flame spread index requirement but shall be required to meet a smoke-developed index of not more than 450 when tested in accordance with CAN/ULC S102.2.

  720.3.1 Attic floors. Exposed insulation materials installed on attic floors shall have a critical radiant flux of not less than 0.12 watt per square centimeter when tested in accordance with ASTM E970.

  720.4 Loose-fill insulation. Loose-fill insulation materials that cannot be mounted in the ASTM E84 or UL 723 apparatus without a screen or artificial supports shall comply with the flame spread and smoke-developed limits of Sections 720.2 and 720.3 when tested in accordance with CAN/ULC S102.2.

  Exception: Cellulosic fiber loose-fill insulation shall not be required to meet a flame spread index requirement when tested in accordance with CAN/ULC S102.2, provided that such insulation has a smoke-developed index of not more than 450 and complies with the requirements of Section 720.6.

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  FIRE AND SMOKE PROTECTION FEATURES

  720.5 Roof insulation. The use of combustible roof insulation not complying with Sections 720.2 and 720.3 shall be permitted in any type of construction provided that insulation is covered with approved roof coverings directly applied thereto.

  720.6 Cellulosic fiber loose-fill insulation and self-supported spray-applied cellulosic insulation. Cellulosic fiber loose-fill insulation and self-supported spray-applied cellulosic insulation shall comply with CPSC 16 CFR Parts 1209 and 1404. Each package of such insulating material shall be clearly labeled in accordance with CPSC 16 CFR Parts 1209 and 1404.

  720.7 Insulation and covering on pipe and tubing. Insulation and covering on pipe and tubing shall have a flame spread index of not more than 25 and a smoke-developed index of not more than 450.

• CBC § 1206.4 Medium relevance — show source text

  Exception: Impact sound insulation is not required for floor-ceiling assemblies over nonhabitable rooms or spaces not designed to be occupied, such as garages, mechanical rooms or storage areas.

  1206.4 Allowable interior noise levels. Interior noise levels attributable to exterior sources shall not exceed 45 dB in any habitable room. The noise metric shall be either the day-night average sound level (Ldn) or the community noise equivalent level (CNEL), consis- tent with the noise element of the local general plan.

  1206.5 Acoustical control. [BSC-CG] See California Green Building Standards Code, Chapter 5, Division 5.5 for additional sound trans- mission requirements.

  SECTION 1207—ENHANCED CLASSROOM ACOUSTICS

  1207.1 General. Enhanced classroom acoustics, where required by this section, shall comply with Section 808 of ICC A117.1.

  1207.2 Where required. In Group E occupancies, enhanced classroom acoustics shall be provided in all classrooms with a volume of 20,000 cubic feet (566 m [3] ) or less.

  SECTION 1208—INTERIOR SPACE DIMENSIONS

  1208.1 Minimum room widths. Habitable spaces, other than a kitchen, shall be not less than 7 feet (2134 mm) in any plan dimension. Kitchens shall have a clear passageway of not less than 3 feet (914 mm) between counter fronts and appliances or counter fronts and walls.

  [HCD 1] For limited-density owner-built rural dwellings, there shall be no requirements for room dimensions, provided there is adequate light and ventilation and adequate means of egress.

  1208.2 Minimum ceiling heights. Occupiable spaces, habitable spaces and corridors shall have a ceiling height of not less than 7 feet 6 inches (2286 mm) above the finished floor. Bathrooms, toilet rooms, kitchens, storage rooms and laundry rooms shall have a ceiling height of not less than 7 feet (2134 mm) above the finished floor.

  Exceptions:

  1. In one- and two-family dwellings, beams or girders spaced not less than 4 feet (1219 mm) on center shall be permitted to project not more than 6 inches (152 mm) below the required ceiling height.
  2. If any room in a building has a sloped ceiling, the prescribed ceiling height for the room is required in one-half the area thereof. Any portion of the room measuring less than 5 feet (1524 mm) from the finished floor to the ceiling shall not be included in any computation of the minimum area thereof.
  3. The height of mezzanines and spaces below mezzanines shall be in accordance with Section 505.2.

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  INTERIOR ENVIRONMENT

  4. Corridors contained within a dwelling unit or sleeping unit in a Group R occupancy shall have a ceiling height of not less than 7 feet (2134 mm) above the finished floor.

  5. [OSHPD 1, 2, 3 & 5] Minimum ceiling heights shall comply with Section 1224.4.10. 6. [OSHPD 4] Minimum ceiling heights shall comply with Section 1227.8.

• CBC § 803.13 Medium relevance — show source text

  Interior finishes Table 803.13, 804 Live load Table 1607.1 Means of egress Corridors 1020.3

  Stairway, exit access 1019

  Travel distance 407, 1006.3, 1017.2,

  1006.2.1

  Mixed occupancies 508.3, 508.4 Occupancy exceptions 303.1.1, 303.1.2, 308.5.1, 308.5.4, 310.4.1 Plumbing fixtures Chapter 29 Risk category Table 1604.5 Standby, emergency power 2702.2 Insulation

  Concealed 720.2

  Duct insulation 720.1

  Exposed 720.3 Fiberboard 720.1, Table 1508.2, 2303.1.6.2, 2303.1.6.3 Foam plastic (see Foam Plastics) 720.1

  Loose fill 720.4, 720.6 Pipe insulation 720.1, 720.7 Reflective plastic core 2614 Roof 720.5, 1508 Sound 720, 807, 1206 Thermal 720, 807, 1508 Interior Environment Lighting 1204 Rodentproofing Appendix F Sound transmission 1206

  Space dimensions 1208 Temperature control 1203 Ventilation 409.3, 414.3, 415.9.1.7,

  1202.5

  Yards or courts 1205.2, 1205.3 Interior Finishes Chapter 8 Acoustical ceiling systems 807, 808 Application 803.13, 804.4 Atriums 404.8 Children’s play structures 424 Covered and open mall buildings 402.6

  Decorative materials 419, 802.3, 806 Floor finish 804, 805 Foam plastic insulation 2603.3, 2603.4 Foam plastic trim 806.6.1, 2604.2 Insulation 807 Light-transmitting plastics 2606 Signs 402.6.4, 2611 Site-fabricated stretch systems 803.10 Trim 806.6, 806.7 Wall and ceiling finishes 803 Wet location 1210 Intermodal Shipping Container 3114 Interpretation, Code 104.1

  Jails [see Institutional (see Group I-3)] 308.5, 408 Joint Gypsum board 2508.5 Lumber sheathing 2308.11.10 Waterproofing 1805.3.3 Joints, Fire-resistant Systems 715 Special inspection 1705.18

  Kiosks 402.6.2

  Kitchens 303.3, 306.2 Accessibility 1133A, 11B-212 Dimensions 1209 Means of egress 1016.2 Occupant load Table 1004.5 Sinks Chapter 29

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  INDEX

  Marquees 3106, H113 Construction 3106.5

• CBC § 2507.2 Medium relevance — show source text

  C587—2004(2018): Specification for Gypsum Veneer Plaster

  Table 2507.2

  C595/C595M—21: Specification for Blended Hydraulic Cements 1909.2.2, 1910A.1, Table 2507.2

  C618—23e1: Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete

  1909.2.2, 1910A.1

  C631—2020: Standard Specification for Bonding Compounds for Interior Gypsum Plastering

  Table 2507.2

  C635/C635M—2017: Specification for the Manufacture, Performance and Testing of Metal Suspension Systems for Acoustical Tile and Lay-In Panel Ceilings

  2506.2.1

  C635/C635M— 22 : Standard Specification for the Manufacture, Performance and Testing of Metal Suspension Systems for Acoustical Tile and Lay-In Panel Ceilings

  2506.2.1, 1617A.1.21

  C636/C636M—19: Practice for Installation of Metal Ceiling Suspension Systems for Acoustical Tile and Lay-In Panels

  808.1.1.1, 1617.11.16, 1617A.1.21

  C652—21: Specification for Hollow Brick (Hollow Masonry Units Made from Clay or Shale)

  1807.1.6.3

  C726—2017: Standard Specification for Mineral Wool Roof Insulation Board

  Table 1508.2

  C728—2017A: Standard Specification for Perlite Thermal Insulation Board

  Table 1508.2

  C744—2016: Specification for Prefaced Concrete and Calcium Silicate Masonry Units

  Table 722.3.2

  C754—20: Specification for Installation of Steel Framing Members to Receive Screw-Attached Gypsum Panel Products Table 2508.1, Table 2511.1.1

  C836/C836M—2018(2022): Specification for High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane for Use with Separate Wearing Course

  1507.14.2

  C840—20: Specification for Application and Finishing of Gypsum Board Table 2508.1, 2509.2

  C841—2003(2018): Standard Specification for Installation of Interior Lathing and Furring Table 2508.1, Table 2511.1.1

  C842—05(2021): Standard Specification for Application of Interior Gypsum Plaster Table 2511.1.1, 2511.3, 2511.4

  C843—2017: Specification for Application of Gypsum Veneer Plaster

  Table 2511.1.1

  2025 CALIFORNIA BUILDING CODE 35-13

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

  REFERENCED STANDARDS

  C844—2015(2021): Specification for Application of Gypsum Base to Receive Gypsum Veneer Plaster

  Table 2508.1

  C847—2018: Specification for Metal Lath

  Table 2507.2

  C887—20: Specification for Packaged, Dry Combined Materials for Surface Bonding Mortar

  1805.2.2, 2103.2.2