CBC · California Building Code

What fire‑classification tests are accepted for wall and ceiling finishes?

The California Building Code accepts two test methods for wall and ceiling finishes: NFPA 286 (a room‑corner fire test) and ASTM E84/UL 723 (a surface flame/spread test). Passing NFPA 286 per §803.1.1.1 is treated as Class A; alternatively ASTM E84 results place materials in Classes A/B/C by flame spread and smoke values per §803.1.2.

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Last reviewed: July 5, 2026

What the code requires — 2–4 sentences

The California Building Code accepts two test paths for classifying wall and ceiling finishes: the room‑corner test NFPA 286 and the surface‑burn test ASTM E84 / UL 723. Materials that meet the NFPA 286 acceptance criteria in §803.1.1 are treated as Class A for purposes of the code; alternatively, materials may be grouped as Class A/B/C based on ASTM E84/UL 723 flame spread and smoke‑developed indices per §803.1.2. See §803.1.1 and §803.1.2 for the controlling requirements.

Requirements in detail

Accepted test standards

  • NFPA 286 (room‑corner, “room fire” test) is an accepted test path and has specific acceptance criteria the finish must meet; materials complying with those criteria are considered to meet Class A. See §803.1.1.
  • ASTM E84 or UL 723 (also called the Steiner tunnel / surface burn test) is the alternative, used to assign Class A, B or C by flame spread and smoke‑developed indices. See §803.1.2.

NFPA 286 acceptance criteria (summary)

When a material is tested per NFPA 286 the CBC requires that all of the following be met (these are the code’s pass conditions):

  1. During the 40 kW exposure the flames must not spread to the ceiling.
  2. 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. Peak heat release rate (HRR) throughout the test shall not exceed 800 kW.
  5. Total smoke released throughout the test shall not exceed 1,000 m2.
    These are the conditions listed in §803.1.1.1; materials meeting them are treated as Class A under the CBC.

ASTM E84 / UL 723 class definitions (summary)

The CBC groups materials tested by ASTM E84 / UL 723 into Classes A, B or C based on flame spread index and smoke‑developed index per §803.1.2:

Classification metric Flame spread index Smoke‑developed index Code Reference
Class A (ASTM E84/UL 723) 0–25 0–450 §803.1.2
Class B (ASTM E84/UL 723) 26–75 0–450 §803.1.2
Class C (ASTM E84/UL 723) 76–200 0–450 §803.1.2
NFPA 286 pass (equivalent) — — NFPA 286 acceptance criteria = Class A per §803.1.1.1 and §803.1.1

Note: ASTM E84 assigns numeric indices; the CBC uses the class ranges above to determine allowable finish in different occupancies/locations (see Table 803.3 and related sections).

Application and configuration notes

  • A material that passes the NFPA 286 acceptance criteria in §803.1.1.1 is considered to comply with Class A and is not required to be retested under ASTM E84/UL 723. §803.1.1 explicitly states materials tested per NFPA 286 need not be tested per §803.1.2.
  • Some sections of Chapter 8 require specific testing for particular materials or configurations (see §803.1.3 et seq.). The code also contains provisions on installation/configuration (for example, limitations on furring, suspended finishes and when the test was conducted with the finish furred/suspended). See §803.1.3 and §803.15 for those situational rules.
  • Stability: finishes must be fastened or applied so they do not readily detach when exposed to 200°F (93°C) for 30 minutes (stability requirement). See §803.2.

Exceptions & special cases

  • Materials tested and passing NFPA 286 (per §803.1.1.1) are treated as Class A and therefore are exempt from separate ASTM E84/UL 723 testing per §803.1.1.
  • Sections §803.1.3 through §803.15 contain material‑specific testing or application rules (for example, foam plastics, acoustical ceilings, set‑out construction, trim). Those sections may require different tests or limit permitted materials in certain situations; consult the specific section that applies to your material or installation.
  • For dropped/set‑out ceilings, furring or suspended finishes the code restricts when such configurations are permitted and when Class A material is required; see §803.15.2 and §803.15.4 for conditions and exceptions.

Common mistakes

  • Assuming NFPA 286 is only for “special cases.” In the CBC NFPA 286 is an accepted test path and passing it is equivalent to Class A (see §803.1.1).
  • Misreading the class ranges: Class A in ASTM E84 is 0–25 flame spread (not 0–200), and the smoke index limit for all classes is 0–450 per §803.1.2.
  • Ignoring smoke metrics: a low flame spread index with smoke‑developed index >450 does not meet the ASTM/UL requirements in §803.1.2.
  • Using test reports where the sample configuration doesn’t match the installed condition (e.g., tested on noncombustible backing but installed suspended/furred)—the code contains specific allowances and limits for furring/suspension; check §803.15 and the exceptions in §803.15.4.
  • Overlooking stability and fastening: code requires finishes to remain attached under elevated temperature exposure (§803.2).

Worked example — concrete scenario

Scenario A — ASTM E84 result:

  • Manufacturer’s ASTM E84 lab report: flame spread index = 30; smoke‑developed index = 300.
  • Classification under CBC: flame spread 30 places the finish in Class B (26–75) and smoke 300 is ≤450, so the material is Class B per §803.1.2. That means it will meet code where a Class B finish is required by Table 803.3 and related occupancy rules.

Scenario B — NFPA 286 result:

  • Lab NFPA 286 report: during 40 kW exposure flames did not reach ceiling, flames did not reach the outer extremity, no flashover, peak HRR = 700 kW (≤800 kW), total smoke = 900 m2 (≤1,000 m2).
  • Outcome: Because all five acceptance items in §803.1.1.1 are met, the material is considered to meet Class A per §803.1.1 and is therefore acceptable where CBC requires Class A finishes.

Related provisions

  • §803.1.1 — Interior finishes tested in accordance with NFPA 286 (acceptance criteria, equivalence to Class A).
  • §803.1.2 — Interior finishes tested in accordance with ASTM E84 / UL 723 (Class A/B/C ranges).
  • §803.1.3 — Sections 803.4 through 803.15 list materials with specific testing requirements.
  • §803.2 — Stability requirement (attachment under 200°F for 30 minutes).
  • §803.15 — Set‑out construction, dropped ceilings and related installation limits and exceptions.
  • §806.6 — Interior trim limits and required classifications for trim materials (cross‑references to ASTM E84 classes).
  • §804 — Interior floor finish requirements (related but uses separate tests and classes).

Code references

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

  • 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 § 3-27 High relevance — show source text

    2025 CALIFORNIA RESIDENTIAL CODE 3-27

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    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 § 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.

    2025 CALIFORNIA FIRE CODE 8-3

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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 § 12-7 High relevance — show source text

    12-7A-4A.7.5 Conditions of acceptance. Should one of the three replicates fail to meet the Condition of Acceptance, three additional tests may be run. All of the additional tests must meet the Condition of Acceptance with an effective peak heat release rate of less than or equal to 25 kW/ft [2] (269 kW/m [2] ).

    2025 CALIFORNIA REFERENCED STANDARDS CODE 49

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    50 2025 CALIFORNIA REFERENCED STANDARDS CODE

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    12-8-1 FIRE-RESISTIVE STANDARDS FOR FIRE PROTECTION

    ROOM FIRE TEST FOR WALL AND CEILING MATERIALS

    STANDARD 12-8-100 ( SEE CHAPTER 35, CALIFORNIA BUILDING CODE )

    STATE FIRE MARSHAL

    Authority: Sections 13143, 13146.1, Health and Safety Code Reference: Sections 13108, 13143, 13146.1, Health and Safety Code

    SCOPE

    Sec. 12-8-101.

    (a) Basic. This standard is intended to evaluate, under a specified fire exposure condition, the contribution to room fire growth provided by wall ceiling and/or floor materials or assemblies. This standard is not intended to evaluate the fire endurance or flamespread of material or assemblies.

    Note: See State Fire Marshal (SFM) 7-1 and Uniform Building Code (UBC) Standard 8-1.

    This standard can be used to evaluate the effectiveness of thermal barriers in restricting the contribution of combustible materials in the wall and floor assemblies to fire growth in a padded safety cell. This standard shall be used in conjunction with ASTM E603-77, “Standard Guide for Room Fire Experiments,” which covers instrumentation, safety precautions and the general effect of various parameters.

    (b) Tests and listings by approved testing agency. Test data for wall and/or ceiling materials or assemblies investigated and tested in accordance with the Standard for Safety established by Underwriters Laboratories, Inc., UL 723C, “Investigation for the Classification of Wall and Ceiling Interior Finish Materials and Assemblies Using a Room Fire Test,” will be acceptable for evaluation against this standard, provided all instrumentation data required by this standard is incorporated in the test and report.

    (c) Test simulation. The test simulates a fire in the comer of an 8-foot by 12-foot (2438 mm by 3657 mm) compartment containing a single open doorway; this can be used to evaluate the relative performance of specific wall, ceiling and floor materials or assemblies when they are used together in the same relationship within an enclosure, in addition to simulating the manner in which they will be used.

    (d) Materials considered. The test may be used for evaluating wall, ceiling and flooring finish materials and assemblies, including panels, tiles, boards, sprayed or brushed coatings, etc.

    FIRE AND SMOKE MEASUREMENTS AND PHOTOGRAPHIC RECORD

    Sec. 12-8-102.

  • 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 § 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 § 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 § 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 § 722.2.1.4.3 High relevance — show source text

    722.2.1.4.3 Nonsymmetrical assemblies. For a wall without finish on one side or having different types or thicknesses of finish on each side, the calculation procedures of Sections 722.2.1.4.1 and 722.2.1.4.2 shall be performed twice, assuming either side of the wall to be the fire-exposed side. The fire-resistance rating of the wall shall not exceed the lower of the two values.

    Exception: For an exterior wall with a fire separation distance greater than 5 feet (1524 mm) the fire shall be assumed to occur on the interior side only.

    722.2.1.4.4 Minimum concrete fire-resistance rating. Where finishes applied to one or both sides of a concrete wall contribute to the fire-resistance rating, the concrete alone shall provide not less than one-half of the total required fire-resistance rating. Additionally, the contribution to the fire resistance of the finish on the nonfire-exposed side of a load-bearing wall shall not exceed one-half the contribution of the concrete alone.

    722.2.1.4.5 Concrete finishes. Finishes on concrete walls that are assumed to contribute to the total fire-resistance rating of the wall shall comply with the installation requirements of Section 722.3.2.5.

    722.2.2 Concrete floor and roof slabs. Reinforced and prestressed floors and roofs shall comply with Section 722.2.2.1. Multicourse floors and roofs shall comply with Sections 722.2.2.2 and 722.2.2.3, respectively.

    722.2.2.1 Reinforced and prestressed floors and roofs. The minimum thicknesses of reinforced and prestressed concrete floor or roof slabs for fire-resistance ratings of 1 hour to 4 hours are shown in Table 722.2.2.1.

    Exception: Minimum thickness shall not be required for floors and ramps within parking garages constructed in accordance with Sections 406.5 and 406.6.

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    FIRE AND SMOKE PROTECTION FEATURES

  • 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 § 715.7 High relevance — show source text

    715.7 Exterior wall/vertical fire barrier intersections. Voids created at the intersection of nonfire-resistance-rated exterior wall assemblies and vertical fire barriers shall be filled with an approved material or system to retard the interior spread of fire and hot

    gases.

    715.8 Curtain wall spandrels. Height and fire-resistance requirements for curtain wall spandrels shall comply with Section 705.9.5. Where Section 705.9.5 does not require fire-resistance-rated curtain wall spandrels, the requirements of Sections 715.4 and 715.5 shall still apply to the intersection between the curtain wall spandrels and the floor.

    715.9 Joints and voids in smoke barriers. Fire-resistant joint systems protecting joints in smoke barriers, and perimeter fire containment systems protecting voids at the intersection of a horizontal smoke barrier and an exterior curtain wall, shall be tested in accordance with the requirements of UL 2079 for air leakage. The L rating of the joint system shall not exceed 5 cubic feet per minute per linear foot (0.00775 m [3] /s m) of joint at 0.30 inch of water (74.7 Pa) for both the ambient temperature and elevated temperature

    tests.

    SECTION 716—OPENING PROTECTIVES

    716.1 General. Opening protectives required by other sections of this code shall comply with the provisions of this section and shall be installed in accordance with NFPA 80.

    TABLE 716.1(1)—MARKING FIRE-RATED GLAZING ASSEMBLIES Col2 Col3
    FIRE TEST STANDARD MARKING DEFINITION OF MARKING
    ASTM E119 or UL 263 W Meets wall assembly criteria.
    ASTM E119 or UL 263 FC Meets floor/ceiling criteriaa
    NFPA 257 or UL 9 OH Meets fire window assembly criteria including the hose stream test.
    NFPA 252 or UL 10B or UL 10C D Meets fire door assembly criteria.
    NFPA 252 or UL 10B or UL 10C H Meets fire door assembly hose stream test.
    NFPA 252 or UL 10B or UL 10C T Meets 450°F temperature rise criteria for 30 minutes
    — XXX The time in minutes of the fire resistance or fire protection rating of the glazing assembly.
    For SI:°C = [(°F) – 32]/1.8.
    a. See Section 2409.1    		 For SI:°C = [(°F) – 32]/1.8.
    a. See Section 2409.1    		 For SI:°C = [(°F) – 32]/1.8.
    a. See Section 2409.1

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    FIRE AND SMOKE PROTECTION FEATURES

    |TABLE 716.1(2)—OPENING FIRE PROTECTION ASSEMBLIES,

  • 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 .

Frequently asked questions

Can NFPA 286 be used instead of ASTM E84/UL 723?

Yes. The CBC explicitly accepts NFPA 286; materials that meet the NFPA 286 acceptance criteria in §803.1.1.1 are considered to comply with Class A and need not be retested under ASTM E84/UL 723.

What numeric limits must NFPA 286 pass to be treated as Class A?

The CBC requires: no ceiling flame spread during the 40 kW exposure; no flame to the sample outer extremity; no flashover; peak HRR ≤ 800 kW; total smoke ≤ 1,000 m2 — see §803.1.1.1.

If an ASTM E84 report shows flame spread 20 but smoke 500, does it meet the code?

No. Although flame spread 20 is within the Class A flame spread range, the smoke‑developed index exceeds the 0–450 limit in §803.1.2, so the material would not meet the ASTM/UL criteria required by the CBC.

Does the tested configuration (furred, suspended, backing) matter?

Yes. The code contains provisions limiting when finishes tested in a particular configuration can be used in another (see §803.15.4 and related exceptions). Always confirm the test specimen configuration matches the intended installation or that the code’s exceptions apply.

Where do I find which class is required for my room or occupancy?

Refer to Table 803.3 and the occupancy/location requirements in Chapter 8 (Section 803) to determine whether a Class A, B or C finish is required for your specific occupancy and location; consult §803.3 and associated tables.

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