CBC · California Building Code

Wall & Ceiling Finishes

This hub explains where the CBC sets fire- and smoke-performance requirements for wall and ceiling finishes, the test standards used, and the key sections to consult.

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Last reviewed: July 5, 2026

Overview

Chapter 8 of the California Building Code governs interior finishes used on walls and ceilings, setting performance limits to control flame spread, heat release and smoke development for different occupancies and locations within a building (see Chapter 8, Sections 801–808) . The chapter requires finishes to be tested and classified by recognized methods—most commonly ASTM E84/UL 723 (Class A, B or C) or NFPA 286 for full-scale room-corner behavior—and specifies acceptance criteria for those tests (§803.1.1–803.1.2) .

This part of the CBC matters because interior finishes directly affect fire growth and smoke propagation indoors; occupancy-based limits and installation rules determine where higher-performing materials (for example, Class A or NFPA 286-compliant materials) are required (§802 and §803) . The chapter also addresses related topics such as set-out/dropped ceilings, furring and concealed spaces (§803.15), and restrictions on decorative materials and trim (see §806) to prevent unexpected fuel loads or hazardous flame spread .

Key places to look in the code for wall and ceiling finish rules are §803 (Wall and Ceiling Finishes), §802 (General interior-finish scope and application), and the test-method provisions in §803.1.1 and §803.1.2 (NFPA 286 and ASTM E84/UL 723, respectively) .

In this section

Code references

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

  • CBC § 5.5 High relevance — show source text

    [BSC-CG] See California Green Building Standards Code, Chapter 5, Division 5.5 for additional finish material pollutant control requirements.

    SECTION 802—GENERAL

    802.1 Interior wall and ceiling finish. The provisions of Section 803 shall limit the allowable fire performance and smoke development of interior wall and ceiling finish materials based on occupancy classification.

    802.2 Interior floor finish. The provisions of Section 804 shall limit the allowable fire performance of interior floor finish materials based on occupancy classification.

    [F] 802.3 Decorative materials and trim. Decorative materials and trim shall be restricted by combustibility, fire performance or flame propagation performance criteria in accordance with Section 806.

    802.4 Applicability. For buildings in flood hazard areas as established in Section 1612.3, interior finishes, trim and decorative materials below the elevation required by Section 1612 shall be flood-damage-resistant materials.

    802.5 Application. Combustible materials shall be permitted to be used as finish for walls, ceilings, floors and other interior surfaces of buildings.

    802.6 Windows. Show windows in the exterior walls of the first story above grade plane shall be permitted to be of wood or of unprotected metal framing.

    802.7 Foam plastics. Foam plastics shall not be used as interior finish except as provided in Section 803.4. Foam plastics shall not be used as interior trim except as provided in Section 806.6.1 or 2604.2. This section shall apply both to exposed foam plastics and to foam plastics used in conjunction with a textile or vinyl facing or cover.

    SECTION 803—WALL AND CEILING FINISHES

    803.1 General. Interior wall and ceiling finish materials shall be classified for fire performance and smoke development in accordance with Section 803.1.1 or 803.1.2, except as shown in Sections 803.1.3 through 803.15. Materials tested in accordance with Section 803.1.1 shall not be required to be tested in accordance with Section 803.1.2.

    803.1.1 Interior wall and ceiling finish materials tested in accordance with NFPA 286. Interior wall and ceiling finish materials shall be classified in accordance with NFPA 286 and comply with Section 803.1.1.1. Materials complying with Section 803.1.1.1 shall be considered to also comply with the requirements of Class A.

    803.1.1.1 Acceptance criteria for NFPA 286. The interior finish shall comply with the following:

    1. During the 40 kW exposure, flames shall not spread to the ceiling.

    2. The flame shall not spread to the outer extremity of the sample on any wall or ceiling.

    3. Flashover, as defined in NFPA 286, shall not occur.

    4. The peak heat release rate throughout the test shall not exceed 800 kW.

    5. The total smoke released throughout the test shall not exceed 1,000 m [2] .

    803.1.2 Interior wall and ceiling finish materials tested in accordance with ASTM E84 or UL 723. Interior wall and ceiling finish materials shall be classified in accordance with ASTM E84 or UL 723. Such interior finish materials shall be grouped in the following classes in accordance with their flame spread and smoke-developed indices.

    Class A = Flame spread index 0–25; smoke-developed index 0–450.

    Class B = Flame spread index 26–75; smoke developed index 0–450.

    Class C = Flame spread index 76–200; smoke-developed index 0–450.

  • CBC § 8-5 High relevance — show source text

    Exception: Compliance with Item 1, 2 or 3 is not required where the materials used to create the concealed space are noncombustible.

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    INTERIOR FINISHES

    803.15.2 Set-out construction. Where walls and ceilings are required to be of fire-resistance-rated or noncombustible construction and walls are set out or ceilings are dropped distances greater than specified in Section 803.15.1, Class A finish materials, in accordance with Section 803.1.1 or 803.1.2, shall be used.

    Exceptions:

    1. Where interior finish materials are protected on both sides by an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2.

    2. Where interior finish materials are attached to noncombustible backing or furring strips installed as specified in Section 803.15.1.1.

    3. Where the combustible void is filled with a noncombustible material.

    803.15.2.1 Hangers and assembly members. The hangers and assembly members of such dropped ceilings that are below the horizontal fire-resistance-rated floor or roof assemblies shall be of noncombustible materials. The construction of each set-out wall and horizontal fire-resistance-rated floor or roof assembly shall be of fire-resistance-rated construction as required elsewhere in this code.

    Exception: In Types III and V construction, fire-retardant-treated wood shall be permitted for use as hangers and assembly members of dropped ceilings.

    803.15.3 Heavy timber construction. Wall and ceiling finishes of all classes as permitted in this chapter that are installed directly against the wood decking or planking of heavy timber construction in Section 602.4.4.2 or 2304.11 or to wood furring strips applied directly to the wood decking or planking shall be fireblocked as specified in Section 803.15.1.1. 803.15.4 Materials. An interior wall or ceiling finish material that is not more than [1] / 4 inch (6.4 mm) thick shall be applied directly onto the wall, ceiling or structural element without the use of furring strips and shall not be suspended away from the building element to which that finish material it is applied.

    Exceptions:

    1. Noncombustible interior finish materials.

    2. Materials that meet the requirements of Class A materials in accordance with Section 803.1.1 or 803.1.2 where the qualifying tests were made with the material furred out from the noncombustible backing shall be permitted to be used with furring strips.

    3. Materials that meet the requirements of Class A materials in accordance with Section 803.1.1 or 803.1.2 where the qualifying tests were made with the material suspended away from the noncombustible backing shall be permitted to be used suspended away from the building element.

    SECTION 804—INTERIOR FLOOR FINISH

    804.1 General. Interior floor finish and floor covering materials shall comply with Sections 804.2 through 804.4.2.

    Exception: In areas except Groups I-2 with detention and I-3, floor finishes and coverings of a traditional type, such as wood, vinyl, linoleum or terrazzo, and resilient floor covering materials that are not composed of fibers.

  • CBC § 8-1 High relevance — show source text

    CHAPTER 8 INTERIOR FINISHES. . . . . . . . . . . . . . . . . . . . . .8-1

    801 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

    802 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

    803 Wall and Ceiling Finishes . . . . . . . . . . . . . . . . . . . . . . . . 8-3

    804 Interior Floor Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6

    805 Combustible Materials in Types I and II Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7

    806 Decorative Materials and Trim . . . . . . . . . . . . . . . . . . . 8-7

    807 Insulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

    808 Acoustical Ceiling Systems . . . . . . . . . . . . . . . . . . . . . . 8-8

    CHAPTER 9 FIRE PROTECTION AND LIFE

    SAFETY SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-1

    901 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7

    902 Fire Pump and Riser Room Size . . . . . . . . . . . . . . . . . . 9-7

    903 Automatic Sprinkler Systems . . . . . . . . . . . . . . . . . . . . 9-8

    904 Alternative Automatic Fire-Extinguishing Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17

    905 Standpipe Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-20

    906 Portable Fire Extinguishers . . . . . . . . . . . . . . . . . . . . . 9-22

    907 Fire Alarm and Detection Systems . . . . . . . . . . . . . . . 9-25

    908 Emergency Alarm Systems . . . . . . . . . . . . . . . . . . . . . 9-43

    909 Smoke Control Systems . . . . . . . . . . . . . . . . . . . . . . . . 9-43

    910 Smoke and Heat Removal . . . . . . . . . . . . . . . . . . . . . . 9-51

  • CBC § 7-21 High relevance — show source text

    713 Shaft Enclosures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21

    714 Penetrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-23

    715 Joints and Voids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-26

    716 Opening Protectives . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-27

    717 Ducts and Air Transfer Openings . . . . . . . . . . . . . . . . 7-34

    718 Concealed Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-40

    719 Fire-Resistance Requirements for Plaster . . . . . . . . 7-42

    720 Thermal- and Sound-Insulating Materials . . . . . . . . 7-42

    721 Prescriptive Fire Resistance. . . . . . . . . . . . . . . . . . . . . 7-43

    722 Calculated Fire Resistance. . . . . . . . . . . . . . . . . . . . . . 7-66

    CHAPTER 7A [SFM] MATERIALS AND CONSTRUCTION

    METHODS FOR EXTERIOR WILDFIRE EXPOSURE . . . . . . . 7A-1

    CHAPTER 8 INTERIOR FINISHES. . . . . . . . . . . . . . . . . . . . . .8-1

    801 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

    802 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

    803 Wall and Ceiling Finishes . . . . . . . . . . . . . . . . . . . . . . . . 8-3

    804 Interior Floor Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6

    805 Combustible Materials in Types I and II Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7

    806 Decorative Materials and Trim . . . . . . . . . . . . . . . . . . . 8-7

    807 Insulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

    808 Acoustical Ceiling Systems . . . . . . . . . . . . . . . . . . . . . . 8-8

    CHAPTER 9 FIRE PROTECTION AND LIFE

  • CBC § 802.1 High relevance — show source text

    SECTION 802—DEFINITIONS

    802.1 Definitions. The following terms are defined in Chapter 2:

    FLAME SPREAD.

    FLAME SPREAD INDEX.

    INTERIOR FLOOR-WALL BASE.

    SITE-FABRICATED STRETCH SYSTEM.

    SMOKE-DEVELOPED INDEX.

    [California Code of Regulations, Title 19, Division 1, §1191] Approved.

    “Approved” means approved by the State Fire Marshal.

    [California Code of Regulations, Title 19, Division 1, §1196] Flame-retardant Chemical.

    “Flame-Retardant Chemical,” as used herein, means any chemical, chemical compound or chemical mixture which when properly applied to a fabric or material will render such fabric or material incapable of supporting combustion to the extent that it will success- fully withstand the tests and meet the specifications promulgated by the State Fire Marshal.

    [California Code of Regulations, Title 19, Division 1, §1201] Nonflammable Material.

    “Nonflammable Material,” as used herein, means a fabric or material which is inherently flame-resistant to the extent that it will meet the requirements of the fire resistance test herein prescribed, but shall not include materials which must be chemically treated or processed after manufacture to make them flame-resistant.

    [California Code of Regulations, Title 19, Division 1, §1202] Place of Public Assemblage.

    “Place of Public Assemblage,” as used herein, means any occupancy mentioned in Sections 13115 or 13119 of the Health and Safety Code.

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    INTERIOR FINISH, DECORATIVE MATERIALS AND FURNISHINGS

    SECTION 803—INTERIOR WALL AND CEILING FINISH IN EXISTING BUILDINGS

    803.1 General. The provisions of this section shall limit the allowable fire performance and smoke development of interior wall and ceiling finishes in existing buildings based on location and occupancy classification. Interior wall and ceiling finishes shall be classified in accordance with Section 803 of the California Building Code . Such materials shall be classified in accordance with NFPA 286, as indicated in Section 803.1.1, or in accordance with ASTM E84 or UL 723, as indicated in Section 803.1.2.

    Materials tested in accordance with Section 803.1.1 shall not be required to be tested in accordance with Section 803.1.2.

    803.1.1 Interior wall and ceiling finish materials tested in accordance with NFPA 286. Interior wall and ceiling finish materials shall be classified in accordance with NFPA 286 and tested in accordance with Section 803.1.1.1. Materials complying with Section 803.1.1.1 shall be considered to comply with the requirements of Class A specified in Section 803.1.2.

    803.1.1.1 Acceptance criteria for NFPA 286. The interior finish shall comply with the following:

    1. During the 40 kW exposure, flames shall not spread to the ceiling.

    2. The flame shall not spread to the outer extremity of the sample on any wall or ceiling.

    3. Flashover, as defined in NFPA 286, shall not occur.

    4. The peak heat release rate throughout the test shall not exceed 800 kW.

    5. The total smoke released throughout the test shall not exceed 1,000 m [2] .

  • CBC § 803.13 High relevance — show source text

    1||X||||||||||||||||||||||| |Table 803.13|||X|||||||||||||||||||||| |804.1|||X|||||||||||||||||||||| |804.4|||X|||||||||||||||||||||| |804.4.1|||X|||||||||||||||||||||| |804.4.2|||X|||||||||||||||||||||| |804.4.3|||X|||||||||||||||||||||| |806.4|||X|||||||||||||||||||||| |806.6|||X||||||||||||||||||||||

    The state agency does not adopt sections identified by the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.

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    8 INTERIOR FINISHES

    User notes:

    About this chapter: Chapter 8 contains the performance requirements for controlling fire growth and smoke propagation within buildings by restricting interior finish and decorative materials. The provisions of this chapter require materials used as interior finishes and decorations to meet certain flame spread index or flame propagation criteria and smoke development criteria based on the relative fire hazard associated with the occupancy. The performance of the material is evaluated based on test standards.

    SECTION 801—SCOPE

    801.1 Scope. The provisions of this chapter shall govern the use of materials used as interior finishes, trim and decorative materials.

    [BSC-CG] See California Green Building Standards Code, Chapter 5, Division 5.5 for additional finish material pollutant control requirements.

    SECTION 802—GENERAL

    802.1 Interior wall and ceiling finish. The provisions of Section 803 shall limit the allowable fire performance and smoke development of interior wall and ceiling finish materials based on occupancy classification.

    802.2 Interior floor finish. The provisions of Section 804 shall limit the allowable fire performance of interior floor finish materials based on occupancy classification.

    [F] 802.3 Decorative materials and trim. Decorative materials and trim shall be restricted by combustibility, fire performance or flame propagation performance criteria in accordance with Section 806.

    802.4 Applicability. For buildings in flood hazard areas as established in Section 1612.3, interior finishes, trim and decorative materials below the elevation required by Section 1612 shall be flood-damage-resistant materials.

    802.5 Application. Combustible materials shall be permitted to be used as finish for walls, ceilings, floors and other interior surfaces of buildings.

    802.6 Windows. Show windows in the exterior walls of the first story above grade plane shall be permitted to be of wood or of unprotected metal framing.

    802.7 Foam plastics. Foam plastics shall not be used as interior finish except as provided in Section 803.4. Foam plastics shall not be used as interior trim except as provided in Section 806.6.1 or 2604.2. This section shall apply both to exposed foam plastics and to foam plastics used in conjunction with a textile or vinyl facing or cover.

    SECTION 803—WALL AND CEILING FINISHES

  • CBC § 803.1 High relevance — show source text

    INTERIOR FINISH, DECORATIVE MATERIALS AND FURNISHINGS

    SECTION 803—INTERIOR WALL AND CEILING FINISH IN EXISTING BUILDINGS

    803.1 General. The provisions of this section shall limit the allowable fire performance and smoke development of interior wall and ceiling finishes in existing buildings based on location and occupancy classification. Interior wall and ceiling finishes shall be classified in accordance with Section 803 of the California Building Code . Such materials shall be classified in accordance with NFPA 286, as indicated in Section 803.1.1, or in accordance with ASTM E84 or UL 723, as indicated in Section 803.1.2.

    Materials tested in accordance with Section 803.1.1 shall not be required to be tested in accordance with Section 803.1.2.

    803.1.1 Interior wall and ceiling finish materials tested in accordance with NFPA 286. Interior wall and ceiling finish materials shall be classified in accordance with NFPA 286 and tested in accordance with Section 803.1.1.1. Materials complying with Section 803.1.1.1 shall be considered to comply with the requirements of Class A specified in Section 803.1.2.

    803.1.1.1 Acceptance criteria for NFPA 286. The interior finish shall comply with the following:

    1. During the 40 kW exposure, flames shall not spread to the ceiling.

    2. The flame shall not spread to the outer extremity of the sample on any wall or ceiling.

    3. Flashover, as defined in NFPA 286, shall not occur.

    4. The peak heat release rate throughout the test shall not exceed 800 kW.

    5. The total smoke released throughout the test shall not exceed 1,000 m [2] .

    803.1.2 Interior wall and ceiling finish materials tested in accordance with ASTM E84 or UL 723. Interior wall and ceiling finishes shall be classified in accordance with ASTM E84 or UL 723. Such interior finish materials shall be grouped in the following classes in accordance with their flame spread and smoke-developed indices: Class A: Flame spread index 0–25; smoke-developed index 0–450. Class B: Flame spread index 26–75; smoke-developed index 0–450. Class C: Flame spread index 76–200; smoke-developed index 0–450.

    Exception: Materials tested in accordance with Section 803.1.1 and as indicated in Sections 803.1.3 through 803.15.

    803.1.3 Interior wall and ceiling finish materials with specific requirements. The materials indicated in Sections 803.4 through 803.15 shall be tested as indicated in the corresponding sections.

    803.2 Stability. Interior finish materials regulated by this chapter shall be applied or otherwise fastened in such a manner that such materials will not readily become detached where subjected to room temperatures of 200°F (93°C) for not less than 30 minutes.

    803.3 Interior finish requirements based on occupancy. Interior wall and ceiling finish shall have a flame spread index not greater than that specified in Table 803.3 for the group and location designated. Interior wall and ceiling finish materials tested in accordance with NFPA 286, and meeting the acceptance criteria of Section 803.1.1.1, shall be used where a Class A classification in accordance with ASTM E84 or UL 723 is required.

    |TABLE 803.

  • CBC § 9.1 High relevance — show source text

    R302.9 Flame spread index and smoke-developed index for wall and ceiling finishes. Flame spread and smoke-developed indices for wall and ceiling finishes shall be in accordance with Sections R302.9.1 through R302.9.4.

    R302.9.1 Flame spread index. Wall and ceiling finishes shall have a flame spread index of not greater than 200.

    Exception: Flame spread index requirements for finishes shall not apply to trim defined as picture molds, chair rails, baseboards and handrails; to doors and windows or their frames; or to materials that are less than [1] / 28 inch (0.91 mm) in thickness cemented to the surface of walls or ceilings if these materials exhibit flame spread index values not greater than those of paper of this thickness cemented to a noncombustible backing.

    R302.9.2 Smoke-developed index. Wall and ceiling finishes shall have a smoke-developed index of not greater than 450.

    R302.9.3 Testing. Tests shall be made in accordance with ASTM E84 or UL 723.

    R302.9.4 Alternative test method. As an alternative to having a flame spread index of not greater than 200 and a smoke-developed index of not greater than 450 where tested in accordance with ASTM E84 or UL 723, wall and ceiling finishes shall be permitted to be tested in accordance with NFPA 286. Materials tested in accordance with NFPA 286 shall meet the following criteria:

    The interior finish shall comply with the following:

    1. During the 40 kW exposure, flames shall not spread to the ceiling.

    2. The flame shall not spread to the outer extremity of the sample on any wall or ceiling.

    3. Flashover, as defined in NFPA 286, shall not occur.

    4. The peak heat release rate throughout the test shall not exceed 800 kW.

    5. The total smoke released throughout the test shall not exceed 1,000 m [2] .

    R302.9.4.1 Stability. Interior finish materials regulated by this chapter shall be applied or otherwise fastened in such a manner that such materials will not readily become detached where subjected to room temperatures of 200°F (93°C) for not less than 30 minutes.

    R302.9.5 High-density polyethylene (HDPE) and polypropylene (PP). Where high-density polyethylene or polypropylene is used as an interior finish material, it shall be tested in accordance with NFPA 286 and comply with the criteria in Section R302.9.4.

    R302.10 Flame spread index and smoke-developed index for insulation. Flame spread and smoke-developed index for insulation shall be in accordance with Sections R302.10.1 through R302.10.4.

    R302.10.1 Insulation. Insulating materials installed within floor-ceiling assemblies, roof-ceiling assemblies, wall assemblies, crawl spaces and attics shall comply with the requirements of this section. They shall exhibit a flame spread index not to exceed 25 and a smoke-developed index not to exceed 450 where tested in accordance with ASTM E84 or UL 723. Insulating materials, where tested in accordance with the requirements of this section, shall include facings, where used, such as vapor retarders, vapor permeable membranes and similar coverings.

    Exceptions:

  • CBC § 806.6. High relevance — show source text

    1. Roof coverings that have an A, B or C classification.

    2. Interior floor finish and floor covering materials installed in accordance with Section 804.

    3. Millwork such as doors, door frames, window sashes and frames.

    4. Interior wall and ceiling finishes installed in accordance with Section 803.

    5. Trim installed in accordance with Section 806.6.

    6. Where not installed greater than 15 feet (4572 mm) above grade, show windows, nailing or furring strips and wooden bulkheads below show windows, including their frames, aprons and show cases.

    7. Finish flooring installed in accordance with Section 805.

    8. Partitions dividing portions of stores, offices or similar places occupied by one tenant only and that do not establish a corridor serving an occupant load of 30 or more shall be permitted to be constructed of fire-retardant-treated wood complying with Section 2303.2, 1-hour fire-resistance-rated construction or of wood panels or similar light construction up to 6 feet (1829 mm) in height.

    9. Stages and platforms constructed in accordance with Sections 410.2 and 410.3, respectively.

    10. Combustible exterior wall coverings, balconies and similar projections and bay or oriel windows in accordance with Chapter 14 and Section 705.2.3.1.

    11. Blocking such as for handrails, millwork, cabinets and window and door frames.

    12. Light-transmitting plastics as permitted by Chapter 26.

    13. Mastics and caulking materials applied to provide flexible seals between components of exterior wall construction.

    14. Exterior plastic veneer installed in accordance with Section 2605.2.

    15. Nailing or furring strips as permitted by Section 803.15.

    16. Heavy timber as permitted by Note c to Table 601 and Sections 602.4.4.4 and 705.2.3.1.

    17. Aggregates, component materials and admixtures as permitted by Section 703.2.1.2.

    18. Sprayed fire-resistive materials and intumescent fire-resistive materials, determined on the basis of fire resistance tests in accordance with Section 703.2 and installed in accordance with Sections 1705.15 and 1705.16, respectively.

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    �

    TYPES OF CONSTRUCTION

    1. Materials used to protect penetrations in fire-resistance-rated assemblies in accordance with Section 714.
    2. Materials used to protect joints in fire-resistance-rated assemblies in accordance with Section 715.
    3. Materials allowed in the concealed spaces of buildings of Types I and II construction in accordance with Section 718.5.
    4. Materials exposed within plenums complying with the California Mechanical Code .
    5. Wall construction of freezers and coolers of less than 1,000 square feet (92.9 m [2] ), in size, lined on both sides with noncombustible materials and the building is protected throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
    6. Wood nailers for parapet flashing and roof cants.
    7. Vapor retarders as required by Section 1404.3.

    603.1.1 Ducts. The use of nonmetallic ducts shall be permitted where installed in accordance with the limitations of the California Mechanical Code .

  • CBC § 903.3.1.1 High relevance — show source text

    Fixed or movable walls and partitions, paneling, wall pads and crash pads applied structurally or for decoration, acoustical correction, surface insulation or other purposes shall be considered to be interior finish, shall comply with Section 803 and shall not be considered to be decorative materials or furnishings.

    Exceptions:

    1. In auditoriums in Group A, the permissible amount of curtains, draperies, fabric hangings and similar combustible decorative materials suspended from walls or ceilings shall not exceed 75 percent of the aggregate wall area where the building is equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1, and where the material is installed in accordance with Section 803.15 of this code.

    2. In Group R-2 dormitories, within sleeping units and dwelling units, the permissible amount of curtains, draperies, fabric hangings and similar decorative materials suspended from walls or ceiling shall not exceed 50 percent of the aggregate wall areas where the building is equipped throughout with an approved automatic sprinkler system installed in accordance with Section 903.3.1.

    3. In Group B and M occupancies, the amount of combustible fabric partitions suspended from the ceiling and not supported by the floor shall comply with Section 806.4 and shall not be limited.

    4. The 10-percent limit shall not apply to curtains, draperies, fabric hangings and similar combustible decorative materials used as window coverings.

    [F] 806.3 Occupancy-based requirements. Occupancy-based requirements for combustible decorative materials, other than decorative vegetation, not complying with Section 806.4 shall comply with Sections 807.5.1 through 807.5.6 of the California Fire Code .

    [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

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

    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.

  • CBC § 3-27 Medium relevance — show source text

    2025 CALIFORNIA RESIDENTIAL CODE 3-27

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

    BUILDING PLANNING

    TABLE R302.6—DWELLING UNIT GARAGE AND/OR CARPORT SEPARATION Col2
    ** SEPARATION** ** MATERIAL**
    From the dwelling unit and attics Not less than1/2-inch gypsum board or equivalent applied to the garage side
    From portions of the dwelling unit above the garage_or carport_ Not less than5/8-inch Type X gypsum board or equivalent
    Structure supporting floor/ceiling assemblies used for separation
    required by this section    		 Not less than1/2-inch gypsum board or equivalent
    Garages located less than 3 feet from a dwelling unit on the same lot Not less than1/2-inch gypsum board or equivalent applied to the interior
    side of exterior walls that are within this area
    For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

    R302.7 Under-stair protection. Enclosed space under stairs that is accessed by a door or access panel shall have walls, under-stair surface and any soffits protected on the enclosed side with [1] / 2 -inch (12.7 mm) gypsum board.

    R302.8 Foam plastics. For requirements for foam plastics, see Section R303.

    R302.8.1 Interior finish. Foam plastics used as interior finishes shall comply with Section R303.5.10.

    R302.9 Flame spread index and smoke-developed index for wall and ceiling finishes. Flame spread and smoke-developed indices for wall and ceiling finishes shall be in accordance with Sections R302.9.1 through R302.9.4.

    R302.9.1 Flame spread index. Wall and ceiling finishes shall have a flame spread index of not greater than 200.

    Exception: Flame spread index requirements for finishes shall not apply to trim defined as picture molds, chair rails, baseboards and handrails; to doors and windows or their frames; or to materials that are less than [1] / 28 inch (0.91 mm) in thickness cemented to the surface of walls or ceilings if these materials exhibit flame spread index values not greater than those of paper of this thickness cemented to a noncombustible backing.

    R302.9.2 Smoke-developed index. Wall and ceiling finishes shall have a smoke-developed index of not greater than 450.

    R302.9.3 Testing. Tests shall be made in accordance with ASTM E84 or UL 723.

    R302.9.4 Alternative test method. As an alternative to having a flame spread index of not greater than 200 and a smoke-developed index of not greater than 450 where tested in accordance with ASTM E84 or UL 723, wall and ceiling finishes shall be permitted to be tested in accordance with NFPA 286. Materials tested in accordance with NFPA 286 shall meet the following criteria:

    The interior finish shall comply with the following:

    1. During the 40 kW exposure, flames shall not spread to the ceiling.
    2. The flame shall not spread to the outer extremity of the sample on any wall or ceiling.
    3. Flashover, as defined in NFPA 286, shall not occur.
  • CBC § 8-3 Medium relevance — show source text

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

    CONTENTS

    802 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

    803 Interior Wall and Ceiling Finish in Existing Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4 804 Interior Wall and Ceiling Trim and Interior Floor Finish in New and Existing Buildings . . . . . . . . . . . . 8-7 805 Upholstered Furniture and Mattresses in New and Existing Buildings . . . . . . . . . . . . . . . . . . . . . . . . . 8-8 806 Natural Decorative Vegetation in New and Existing Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10 807 Decorative Materials and Artificial Decorative Vegetation in New and Existing Buildings. . . . . . . 8-10 808 Furnishings Other than Upholstered Furniture and Mattresses or Decorative Materials in New and Existing Buildings. . . . . . . . . . . . . . . . . . . . 8-14

    CHAPTER 9 FIRE PROTECTION AND LIFE SAFETY

    SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7

    901 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7

    902 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11

    903 Automatic Sprinkler Systems. . . . . . . . . . . . . . . . . . . . 9-13 904 Alternative Automatic Fire-Extinguishing Systems . 9-24 905 Standpipe Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-28 906 Portable Fire Extinguishers. . . . . . . . . . . . . . . . . . . . . . 9-31 907 Fire Alarm and Detection Systems . . . . . . . . . . . . . . . 9-39 908 Emergency Alarm Systems . . . . . . . . . . . . . . . . . . . . . . 9-57 909 Smoke Control Systems. . . . . . . . . . . . . . . . . . . . . . . . . 9-57 910 Smoke and Heat Removal. . . . . . . . . . . . . . . . . . . . . . . 9-66

Frequently asked questions

What test standards classify wall and ceiling finishes?

Finishes are classified by ASTM E84/UL 723 into flame-spread/smoke classes (Class A, B, C) or evaluated using NFPA 286 for room-corner/full-scale criteria; both methods and the acceptance criteria are referenced in §803.1.1–803.1.2 .

When is a Class A or NFPA 286-compliant finish required?

Higher-performance (Class A or NFPA 286-compliant) finishes are required where Table 803.3, occupancy limits, or specific construction conditions (for example set-out or dropped ceilings) mandate them; see §803 and §803.15 for those location- and application-based rules .

Are combustible trims and decorative materials allowed?

Yes, but combustible trim and decorative materials are restricted by §806 and have occupancy-based fire-performance limits (trim percentage limits, minimum class requirements, and testing/acceptance rules) to limit added fire hazard .

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