CBC · California Building Code

What roof fire classifications are required and how are Class A/B/C defined?

The CBC requires many roofs to be Class A, B or C depending on building construction and location. Class A is the most fire‑resistant (severe exposure), Class B is moderate, and Class C is light exposure. Required classifications are set in Table 1505.1 and the roof materials or assemblies must be listed and tested (ASTM E108/UL 790) when the code requires it; special rules apply in the Wildland‑Urban Interface and for reroofing and PV systems. § 1505.1, § 1505.2, § 1505.3, § 1505.4, § 1505.6

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Last reviewed: July 5, 2026

What the code requires — 2-4 sentences

The California Building Code (CBC) requires roof assemblies to meet minimum fire classifications (Class A, B or C) based on the building’s type of construction and location; those minimums are set in Table 1505.1 and the general rules are in § 1505.1. Class A, B and C are defined by their level of effectiveness under fire testing (severe, moderate, light respectively) and must be listed by an approved testing agency and tested to ASTM E108 or UL 790 when required. Additional location-based rules (e.g., Wildland-Urban Interface) and reroofing triggers are in the same section. § 1505.1, § 1505.2, § 1505.3, § 1505.4, § 1505.6

Requirements in detail

Basic framework

  • Minimum roof classification is determined by the building’s type of construction using Table 1505.1; the general fire-classification requirements are in § 1505.1. Roof assemblies required to be classified must be tested to ASTM E108 or UL 790 and listed/identified by an approved testing agency. § 1505.1
  • Class definitions:
    • Class A = effective against severe fire-test exposure (highest level). § 1505.2
    • Class B = effective against moderate fire-test exposure. § 1505.3
    • Class C = effective against light fire-test exposure. § 1505.4
  • Testing/listing: Where a classification is required the roof assembly or covering must be listed and identified by an approved testing agency and tested per ASTM E108 or UL 790 (per § 1505.1). § 1505.1

Decision‑relevant table

Decision factor Typical values/choices Minimum or effect Code Reference
Type of construction (e.g., IA, IB, IIA, IIB, IIIA, IIIB, IV, VA, VB) See Table 1505.1 mapping Minimum required roof class varies by construction type (B or C in many cases; some B required for I/III/VA types) Table 1505.1 / § 1505.1
Required test standard for listed materials ASTM E108 or UL 790 Required when a class is mandated § 1505.1
Reroofing / replacement trigger New structure OR >50% roof replaced in 1 year Roof must be at least Class C (fire-retardant roof covering) outside WUI/FHSZ requirements § 1505.1.2 (see § 1505.1)
Fire‑retardant-treated wood shakes/shingles Must meet UBC standards, ASTM E108/UL 790 and ICC‑ES EG107; weathering per HSC §13132.7(j) May be used on Class A/B/C roofs when listed and labeled § 1505.6
Building‑integrated or rooftop PV BIPV must be listed/labeled for fire classification; rooftop PV per UL 2703 and must meet Table 1505.1 Fire classification requirement applies to PV systems and must match Table 1505.1 minimums § 1505.8, § 1505.9

(Use the full Table 1505.1 to determine the specific class required for each construction type and any footnote exceptions.) § 1505.1 / Table 1505.1

Class A exceptions and common listed materials

The CBC specifically lists several materials/assemblies that qualify as Class A by exception (for example brick, masonry, exposed concrete deck; certain metal, clay/concrete tile, slate on noncombustible decks; and specified copper sheet installations). These exceptions are provided in § 1505.2. § 1505.2

Exceptions & special cases

  • Wildland-Urban Interface / Fire Hazard Severity Zones: Roofing in those areas must also comply with WUI provisions (see § 1505.1.1 and Section 705A); those local/overlay rules can impose stricter requirements than the baseline Table 1505.1. § 1505.1.1
  • Reroofing: Outside WUI/FHSZ, when a new structure is built or when >50% of an existing roof is replaced within a 1‑year period, the applicable roof covering must be a fire‑retardant roof covering of at least Class C. § 1505.1.2
  • Nonclassified roofing: Some approved materials that are not listed as Class A/B/C are allowed in limited situations—e.g., Group U accessory buildings with minimum 6 ft fire‑separation from the roof leading edge (see Table 1505.1 footnotes). Table 1505.1 (footnotes) / § 1505.1
  • Fire‑retardant‑treated wood shingles/shakes: Allowed when they meet UBC/ASTM/ICC‑ES and State Fire Marshal weathering/listing requirements; bundles must bear required labels. § 1505.6
  • Photovoltaic systems: BIPV must be tested/listed for roof fire classification per § 1505.1; rooftop PV modules/systems must be listed to UL 2703 and meet Table 1505.1 minimums. § 1505.8, § 1505.9

If a specific material or manufacturer claim is not explicitly listed in the code excerpts you provide, check the product listing (approved testing agency label) and the building official’s interpretation before assuming compliance — the code requires listing/identification for required classifications. § 1505.1

Common mistakes

  • Relying on generic product marketing rather than a valid listing: the CBC requires products to be “listed and identified” as Class A, B or C by an approved testing agency when the classification is required. Do not accept a manufacturer statement without the listing label or report. § 1505.1, § 1505.2–1505.4
  • Forgetting location-based rules (WUI / Fire Hazard Severity Zones): those overlay rules can impose stricter minimums than Table 1505.1; always check § 1505.1.1 and local WUI rules. § 1505.1.1
  • Assuming reroofing is a repair: major reroofing or replacement (>50% in 1 year) often triggers a requirement to upgrade to at least Class C (outside WUI), so calculate the replaced area before deciding materials. § 1505.1.2
  • Using nonclassified roofing without verifying applicable footnotes/occupancy exceptions: nonclassified roofing is limited (e.g., Group U with distances). Check Table 1505.1 footnotes. Table 1505.1 / § 1505.1
  • Missing fire‑retardant wood labeling/weathering requirements: wood shakes/shingles used as fire‑retardant‑treated products must meet the ICC‑ES and State Fire Marshal weathering rules and be labeled. § 1505.6

Worked example — concrete scenario

Scenario: A new Type VB (ordinary light‑frame, VB) commercial building is proposed. The owner asks: what minimum roof classification is required? Use Table 1505.1 to determine the minimum classification for Type VB.

Step 1 — Consult Table 1505.1 for Type VB: Table 1505.1 shows the minimum required roof class for each construction type; for Type VB the table entry indicates Class C in many cases (see table and footnotes for limitations). Confirm with the table in § 1505.1. Table 1505.1 / § 1505.1

Step 2 — Check exceptions/occupancy limits and site overlays:

  • If the building is in a Wildland-Urban Interface, WUI rules may require Class A or higher — see § 1505.1.1. § 1505.1.1
  • If reroofing more than 50% or building is new, the rule that requires at least Class C for many situations (outside WUI) applies — § 1505.1.2. § 1505.1.2

Step 3 — Verify product listing: For whatever roof covering is chosen (e.g., a single‑ply membrane or metal panel), confirm it is listed/identified as Class C (or higher if required) by an approved testing agency and tested to ASTM E108/UL 790 where the code requires listing. § 1505.1

Conclusion for this example: If no overlay (WUI/FHSZ) applies, Type VB usually can use a Class C listed roof covering per Table 1505.1, but confirm footnotes (e.g., area/separation exceptions) and product listings. Table 1505.1 / § 1505.1

Related provisions

  • § 1505.1 — General rules and Table 1505.1 (minimum classifications)
  • § 1505.2 — Class A roof assemblies (definition and exceptions)
  • § 1505.3 — Class B roof assemblies (definition)
  • § 1505.4 — Class C roof assemblies (definition)
  • § 1505.6 — Fire‑retardant‑treated wood shakes and shingles requirements and labeling/weathering criteria
  • § 1505.7 — Special‑purpose roofs (wood shake/shingle application and underlayment)
  • § 1505.8 — Building‑integrated PV (BIPV) fire classification requirements
  • § 1505.9 — Rooftop PV system listing and UL 2703; classification must comply with Table 1505.1
  • § 1506 — Materials and product identification requirements for roof coverings (see labeling and delivery requirements)
  • § 1507 — Installation/covering application standards (see Chapter 15 coverage)

Code references

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

  • CBC § 1505.3 High relevance — show source text
    1. Class A roof assemblies include slate installed over ASTM D226, Type II or ASTM D4869, Type IV underlayment over combustible decks.

    [BF] 1505.3 Class B roof assemblies. Class B roof assemblies are those that are effective against moderate fire-test exposure. Class B roof assemblies and roof coverings shall be listed and identified as Class B by an approved testing agency.

    [BF] 1505.4 Class C roof assemblies. Class C roof assemblies are those that are effective against light fire-test exposure. Class C roof assemblies and roof coverings shall be listed and identified as Class C by an approved testing agency.

    [BF] 1505.5 Nonclassified roofing. Nonclassified roofing is approved material that is not listed as a Class A, B or C roof covering assembly or roof covering.

    [BF] 1505.6 Fire-retardant-treated wood shingles and shakes. Fire-retardant-treated wood shakes and shingles are wood shakes and shingles complying with UBC Standard 15-3 or 15-4 which are impregnated by the full-cell vacuum-pressure process with fire-retar- dant chemicals, and which have been qualified by UBC Standard 15-2 or ASTM E108 or UL 790 for use on Class A, B or C roofs.

    Fire-retardant-treated wood shakes and shingles shall comply with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7(j). Each bundle shall bear labels from an ICC accredited quality control agency identifying their roof-covering classification and indicating their compliance with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7(j).

    Health and Safety Code Section 13132.7(j). No wood roof covering materials shall be sold or applied in this state unless both of the following conditions are met: (1) The materials have been approved and listed by the State Fire Marshal as complying with the requirements of this section. (2) The materials have passed at least five years of the 10-year natural weathering test. The 10-year natural weathering test required by this subdivision shall be conducted in accordance with standard 15-2 of the 1994 edition of the Uniform Building Code at a testing facility recognized by the State Fire Marshal.

    [BF] 1505.7 Special purpose roofs. Special purpose wood shingle or wood shake roofing shall conform to the grading and application requirements of Section 1507.8 or 1507.9. In addition, an underlayment of [5] / 8 -inch (15.9 mm) Type X water-resistant gypsum backing board or gypsum sheathing shall be placed under minimum nominal [1] / 2 -inch-thick (12.7 mm) wood structural panel solid sheathing or 1-inch (25 mm) nominal spaced sheathing.

    [BF] 1505.8 Building-integrated photovoltaic (BIPV) systems. BIPV products installed as the roof covering shall be tested, listed and labeled for fire classification in accordance with Section 1505.1.

    [BF] 1505.9 Rooftop mounted photovoltaic (PV) panel systems. Rooftop mounted photovoltaic (PV) panel systems shall be tested, listed and identified with a fire classification in accordance with UL 2703. Listed systems shall be installed in accordance with the manufacturer’s installation instructions and their listing. The fire classification shall comply with Table 1505.1 based on the type of construction of the building.

  • CBC § 4.882 High relevance — show source text

    Chapter 9 also provides requirements for roof drainage, flashing, above-deck thermal insulation, rooftop-mounted photovoltaic systems and recovering or replacing an existing roof covering.

    SECTION R901—GENERAL

    R901.1 Scope. The provisions of this chapter shall govern the design, materials, construction and quality of roof assemblies.

    SECTION R902—FIRE CLASSIFICATION

    R902.1 Roof assemblies. Roof decks shall be covered with materials as set forth in Section R904 or with roof coverings as set forth in Section R905. A minimum Class A, B or C roofing shall be installed in areas designated by this section or where the edge of the roof deck is less than 3 feet (914 mm) from a lot line. Where Class A, B or C roof assemblies are required, they shall be tested in accordance with ASTM E108 or UL 790. Where required, the roof assembly shall be listed and identified as to class by an approved testing agency.

    Exceptions:

    1. Class A roof assemblies include those with coverings of brick, masonry and exposed concrete roof deck.

    2. Class A roof assemblies include ferrous or copper shingles or sheets, metal sheets and shingles, clay or concrete roof tile, or slate installed on noncombustible roof decks or ferrous, copper or metal sheets installed without a roof deck on noncombustible framing.

    3. Class A roof assemblies include minimum 16 ounces per square foot (4.882 kg/m [2] ) copper sheets installed over combustible roof decks.

    4. Class A roof assemblies include slate installed over underlayment over ASTM D226, Type II underlayment over combustible decks.

    R902.1.1 Roofing requirements within Fire Hazard Severity Zones or in Wildland-Urban Interface (WUI) area. Roofing require- ments for structures located within Fire Hazard Severity Zones or in a Wildland-Urban Interface (WUI) area shall also comply with Part 7, California Wildland-Urban Interface Code.

    R902.1.2 Roof coverings in all other areas other than Fire Hazard Severity Zones or a Wildland-Urban Interface (WUI) area. The entire roof covering of every existing structure where more than 50 percent of the total roof area is replaced within any one-year period, the entire roof covering of every new structure, and any roof covering applied in the alteration, repair or replacement of the roof of every existing structure, shall be a fire-retardant roof covering that is at least Class C fire classification.

    R902.2 Fire-retardant-treated shingles and shakes. Fire-retardant-treated wood shakes and shingles are wood shakes and shin- gles complying with UBC Standard 15-3 or 15-4 which are impregnated by the full-cell vacuum-pressure process with fire-retardant chemicals, and which have been qualified by UBC Standard 15-2 or ASTM E108 or UL 790 for use on Class A, B or C roofs. Fire-retardant- treated wood shakes and shingles shall comply with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7 (j). Each bundle shall bear labels from an ICBO accredited quality control agency identifying their roof-covering classification and indicating their compliance with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7 (j).

  • CBC § 1505.1.1 High relevance — show source text

    ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

    1505.1.1 Roofing requirements within Fire Hazard Severity Zones or in the Wildland-Urban Interface (WUI). Roofing require- ments for structures located within Fire Hazard Severity Zones or in the Wildland-Urban Interface (WUI) shall also comply with Section 705A.

    1505.1.2 Roof coverings within all other areas other than Fire Hazard Severity Zones or a Wildland-Urban Interface (WUI). The entire roof covering of every existing structure where more than 50 percent of the total roof area is replaced within any one-year period, the entire roof covering of every new structure, and any roof covering applied in the alteration, repair or replacement of the roof of every existing structure, shall be a fire-retardant roof covering that is at least Class C fire classification.

    [BF] 1505.2 Class A roof assemblies. Class A roof assemblies are those that are effective against severe fire test exposure. Class A roof assemblies and roof coverings shall be listed and identified as Class A by an approved testing agency. Class A roof assemblies shall be permitted for use in buildings or structures of all types of construction.

    Exceptions:

    1. Class A roof assemblies include those with coverings of brick, masonry or an exposed concrete roof deck.

    2. Class A roof assemblies also include ferrous or copper shingles or sheets, metal sheets and shingles, clay or concrete roof tile or slate installed on noncombustible decks or ferrous, copper or metal sheets installed without a roof deck on noncombustible framing.

    3. Class A roof assemblies include minimum 16 ounce per square foot (0.0416 kg/m [2] ) copper sheets installed over combustible decks.

    4. Class A roof assemblies include slate installed over ASTM D226, Type II or ASTM D4869, Type IV underlayment over combustible decks.

    [BF] 1505.3 Class B roof assemblies. Class B roof assemblies are those that are effective against moderate fire-test exposure. Class B roof assemblies and roof coverings shall be listed and identified as Class B by an approved testing agency.

    [BF] 1505.4 Class C roof assemblies. Class C roof assemblies are those that are effective against light fire-test exposure. Class C roof assemblies and roof coverings shall be listed and identified as Class C by an approved testing agency.

    [BF] 1505.5 Nonclassified roofing. Nonclassified roofing is approved material that is not listed as a Class A, B or C roof covering assembly or roof covering.

    [BF] 1505.6 Fire-retardant-treated wood shingles and shakes. Fire-retardant-treated wood shakes and shingles are wood shakes and shingles complying with UBC Standard 15-3 or 15-4 which are impregnated by the full-cell vacuum-pressure process with fire-retar- dant chemicals, and which have been qualified by UBC Standard 15-2 or ASTM E108 or UL 790 for use on Class A, B or C roofs.

    Fire-retardant-treated wood shakes and shingles shall comply with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7(j). Each bundle shall bear labels from an ICC accredited quality control agency identifying their roof-covering classification and indicating their compliance with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7(j).

  • CBC § 1.0 High relevance — show source text

    Extrapolation is not permitted.
    c. Basic wind speed,V, and wind exposure shall be determined in accordance with Section 1609.
    d. Where the minimum required parapet height is indicated to be 2 inches (51 mm), a gravel stop shall be permitted and shall extend not less than 2 inches (51 mm) from the roof
    surface and not less than the height of the aggregate.
    e. The tabulated values apply only to conditions where the topographic factor (Kzt) determined in accordance with Chapter 26 of ASCE 7 is 1.0 or where_Kzt_ is incorporated in the
    basic wind speed in Section 1609.
    f. For Exposure D, add 8 inches (203 mm) to the parapet height required for Exposure C and the parapet height shall not be less than 12 inches (305 mm).|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
    a. Parapet height is measured vertically from the top surface of the coping down to the surface of the roof covering in the field of the roof adjacent to the parapet and outbound
    of any cant strip.
    b. Interpolation shall be permitted for wind speed, mean roof height and parapet height. Extrapolation is not permitted.
    c. Basic wind speed,V, and wind exposure shall be determined in accordance with Section 1609.
    d. Where the minimum required parapet height is indicated to be 2 inches (51 mm), a gravel stop shall be permitted and shall extend not less than 2 inches (51 mm) from the roof
    surface and not less than the height of the aggregate.
    e. The tabulated values apply only to conditions where the topographic factor (Kzt) determined in accordance with Chapter 26 of ASCE 7 is 1.0 or where_Kzt_ is incorporated in the
    basic wind speed in Section 1609.
    f. For Exposure D, add 8 inches (203 mm) to the parapet height required for Exposure C and the parapet height shall not be less than 12 inches (305 mm).|

    SECTION 1505—FIRE CLASSIFICATION

    [BF] 1505.1 General. Fire classification of roof assemblies shall be in accordance with Section 1505. The minimum fire classification of roof assemblies installed on buildings shall comply with Table 1505.1 based on type of construction of the building. Class A, B and C roof assemblies and roof coverings required to be listed by this section shall be tested in accordance with ASTM E108 or UL 790. In addition, fire-retardant-treated woodroof coverings shall be tested in accordance with ASTM D2898; fire-retardant-treated shingles and shakes shall comply with Section 1505.6.

    Exception: Skylights and sloped glazing that comply with Chapter 24 or Section 2610.

  • CBC § 1.0 High relevance — show source text

    Interpolation shall be permitted for wind speed, mean roof height and parapet height. Extrapolation is not permitted.
    c. Basic wind speed,V, and wind exposure shall be determined in accordance with Section 1609.
    d. Where the minimum required parapet height is indicated to be 2 inches (51 mm), a gravel stop shall be permitted and shall extend not less than 2 inches (51 mm) from the roof
    surface and not less than the height of the aggregate.
    e. The tabulated values apply only to conditions where the topographic factor (Kzt) determined in accordance with Chapter 26 of ASCE 7 is 1.0 or where_Kzt_ is incorporated in the
    basic wind speed in Section 1609.
    f. For Exposure D, add 8 inches (203 mm) to the parapet height required for Exposure C and the parapet height shall not be less than 12 inches (305 mm).|

    SECTION 1505—FIRE CLASSIFICATION

    [BF] 1505.1 General. Fire classification of roof assemblies shall be in accordance with Section 1505. The minimum fire classification of roof assemblies installed on buildings shall comply with Table 1505.1 based on type of construction of the building. Class A, B and C roof assemblies and roof coverings required to be listed by this section shall be tested in accordance with ASTM E108 or UL 790. In addition, fire-retardant-treated woodroof coverings shall be tested in accordance with ASTM D2898; fire-retardant-treated shingles and shakes shall comply with Section 1505.6.

    Exception: Skylights and sloped glazing that comply with Chapter 24 or Section 2610.

    [BF] TABLE 1505.1—MINIMUM ROOF ASSEMBLY CLASSIFICATION FOR TYPES OF CONSTRUCTIONa, b Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9
    IA IB IIA IIB IIIA IIIB IV VA VB
    B B B Cc B Cc B B Cc
    For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2.
    a. Unless otherwise required in accordance with the_California Wildland-Urban Interface Code_ or due to the location of the building within a fire district in accordance with
    Appendix D.
    b. Nonclassified roof coverings shall be permitted on buildings of Group U occupancies, where there is a minimum fire-separation distance of 6 feet measured from the leading
    edge of the roof.
    c. Buildings that are not more than two stories above grade plane and having not more than 6,000 square feet of projected roof area and where there is a minimum 10-foot fire-
    separation distance from the leading edge of the roof to a lot line on all sides of the building, except for street fronts or public ways, shall be permitted to have roofs of No. 1
    cedar or redwood shakes and No. 1 shingles constructed in accordance with Section 1505.7.    		 For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2.
    a. Unless otherwise required in accordance with the_California Wildland-Urban Interface Code_ or due to the location of the building within a fire district in accordance with
    Appendix D.
    b.
  • CBC § 4.1 High relevance — show source text

    1|||X||||||||||||||||||||| |R902.1 - R902.4|||X||||||||||||||||||||| |R903.4.1||||X|||||||||||||||||||| |R904.1 - R904.4|||X||||||||||||||||||||| |R905.15||||X|||||||||||||||||||| |R905.16||||X|||||||||||||||||||| |R907.1||||X|||||||||||||||||||| |R907.2 – R907.5|||X||||||||||||||||||||| |R909|||X|||||||||||||||||||||

    The state agency does not adopt sections identified with the following symbol: †

    2025 CALIFORNIA RESIDENTIAL CODE 9-1

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

    9-2 2025 CALIFORNIA RESIDENTIAL CODE

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

    9 ROOF ASSEMBLIES

    User notes:

    About this chapter: Chapter 9 addresses the design and construction of roof assemblies. A roof assembly includes the roof deck, substrate or thermal barrier, insulation, vapor retarder and roof covering. This chapter provides the requirement for wind resistance of roof coverings. The types of roof covering materials and installation addressed by Chapter 9 are: asphalt shingles, clay and concrete tile, metal roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shakes and shingles, built-up roofs, metal roof panels, modified bitumen roofing, thermoset and thermoplastic single-ply roofing, sprayed polyurethane foam roofing, liquid applied coatings and building-integrated photovoltaic (BIPV) roof coverings. Chapter 9 also provides requirements for roof drainage, flashing, above-deck thermal insulation, rooftop-mounted photovoltaic systems and recovering or replacing an existing roof covering.

    SECTION R901—GENERAL

    R901.1 Scope. The provisions of this chapter shall govern the design, materials, construction and quality of roof assemblies.

    SECTION R902—FIRE CLASSIFICATION

    R902.1 Roof assemblies. Roof decks shall be covered with materials as set forth in Section R904 or with roof coverings as set forth in Section R905. A minimum Class A, B or C roofing shall be installed in areas designated by this section or where the edge of the roof deck is less than 3 feet (914 mm) from a lot line. Where Class A, B or C roof assemblies are required, they shall be tested in accordance with ASTM E108 or UL 790. Where required, the roof assembly shall be listed and identified as to class by an approved testing agency.

    Exceptions:

    1. Class A roof assemblies include those with coverings of brick, masonry and exposed concrete roof deck.

    2. Class A roof assemblies include ferrous or copper shingles or sheets, metal sheets and shingles, clay or concrete roof tile, or slate installed on noncombustible roof decks or ferrous, copper or metal sheets installed without a roof deck on noncombustible framing.

    3. Class A roof assemblies include minimum 16 ounces per square foot (4.882 kg/m [2] ) copper sheets installed over combustible roof decks.

    4. Class A roof assemblies include slate installed over underlayment over ASTM D226, Type II underlayment over combustible decks.

  • CBC § 1505.7. High relevance — show source text

    Buildings that are not more than two stories above grade plane and having not more than 6,000 square feet of projected roof area and where there is a minimum 10-foot fire-
    separation distance from the leading edge of the roof to a lot line on all sides of the building, except for street fronts or public ways, shall be permitted to have roofs of No. 1
    cedar or redwood shakes and No. 1 shingles constructed in accordance with Section 1505.7.|For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2.
    a. Unless otherwise required in accordance with the_California Wildland-Urban Interface Code_ or due to the location of the building within a fire district in accordance with
    Appendix D.
    b. Nonclassified roof coverings shall be permitted on buildings of Group U occupancies, where there is a minimum fire-separation distance of 6 feet measured from the leading
    edge of the roof.
    c. Buildings that are not more than two stories above grade plane and having not more than 6,000 square feet of projected roof area and where there is a minimum 10-foot fire-
    separation distance from the leading edge of the roof to a lot line on all sides of the building, except for street fronts or public ways, shall be permitted to have roofs of No. 1
    cedar or redwood shakes and No. 1 shingles constructed in accordance with Section 1505.7.|

    2025 CALIFORNIA BUILDING CODE 15-5

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

    ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

    1505.1.1 Roofing requirements within Fire Hazard Severity Zones or in the Wildland-Urban Interface (WUI). Roofing require- ments for structures located within Fire Hazard Severity Zones or in the Wildland-Urban Interface (WUI) shall also comply with Section 705A.

    1505.1.2 Roof coverings within all other areas other than Fire Hazard Severity Zones or a Wildland-Urban Interface (WUI). The entire roof covering of every existing structure where more than 50 percent of the total roof area is replaced within any one-year period, the entire roof covering of every new structure, and any roof covering applied in the alteration, repair or replacement of the roof of every existing structure, shall be a fire-retardant roof covering that is at least Class C fire classification.

    [BF] 1505.2 Class A roof assemblies. Class A roof assemblies are those that are effective against severe fire test exposure. Class A roof assemblies and roof coverings shall be listed and identified as Class A by an approved testing agency. Class A roof assemblies shall be permitted for use in buildings or structures of all types of construction.

    Exceptions:

    1. Class A roof assemblies include those with coverings of brick, masonry or an exposed concrete roof deck.
    2. Class A roof assemblies also include ferrous or copper shingles or sheets, metal sheets and shingles, clay or concrete roof tile or slate installed on noncombustible decks or ferrous, copper or metal sheets installed without a roof deck on noncombustible framing.
    3. Class A roof assemblies include minimum 16 ounce per square foot (0.0416 kg/m [2] ) copper sheets installed over combustible decks.
  • CBC § 1.1 High relevance — show source text

    Flame spread, smoke production and degree of combustibility are discussed in detail below. Test results for eight common species of lumber, published in an Underwriter’s Laboratories’ (UL) report (104), are noted in the following table:

    TABLE 1.1
    TUNNEL TEST RESULTS FOR EIGHT SPECIES OF LUMBER    		 Col2 Col3 Col4
    SPECIES OF LUMBER FLAME SPREAD FUEL CONTRIBUTED SMOKE DENSITY
    Western White Pine 75 50-60 50
    Northern White Pine 120–215 120–140 60–65
    Ponderosa Pine 80–215 120–135 100–110
    Yellow Pine 180–190 130–145 275–305
    Red Gum 140–155 125–175 40–60
    Yellow Birch 105–110 100–105 45–65
    Douglas Fir 65–100 50–80 10–100
    Western Hemlock 60—75 40—65 40—120

    Flame Spread

    The flame spread of interior finishes is most often measured by the ASTM E84 “tunnel test.” This test measures how far and how fast the flames spread across the surface of the test sample. The resulting flame spread rating (FSR) is expressed as a number on a continuous scale where cement-asbestos board is 0 and red oak is 100. (Materials with a flame spread greater than red oak have an FSR greater than 100.) The scale is divided into distinct groups or classes. The most commonly used flame spread classifications are:

    – – – Class I or A, with a 0 25 FSR; Class II or B, with a 26 75 FSR; and Class III or C, with a 76 200 FSR. (Note: Some codes use Roman

    – numerals and others use letters.) The NFPA Life Safety Code also has a Class D (201 500 FSR) and Class E (over 500 FSR) interior finish.

    These classifications are typically used in modern building codes to restrict the rate of fire spread. Only the first three classifications are normally permitted, though not all classes of materials can be used in all places throughout a building. For example, the interior finish of building materials used in exits or in corridors leading to exits is more strictly regulated than materials used within private dwelling units.

    In general, inorganic archaic materials (e.g., bricks or tile) can be expected to be in Class I. Materials of whole wood are mostly Class II. Whole wood is defined as wood used in the same form as sawn from the tree. This is in contrast to the contemporary reconstituted wood products such as plywood, fiberboard, hardboard or particle board. If the organic archaic material is not whole wood, the flame spread classification could be well over 200 and thus would be particularly unsuited for use in exits and other critical locations in a building. Some plywoods and various wood fiberboards have flame spreads over 200. Although they can be treated with fire retardants to reduce their flame spread, it would be advisable to assume that all such products have a flame spread over 200 unless there is information to the contrary.

    Smoke Production

  • CBC § 8-409 High relevance — show source text

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

    FIRE PROTECTION

    1. Wooden roof materials may be utilized where fire resistance is required, provided they are treated with fire-retardant treatments to achieve a Class “B” roof covering rating. Wood roofing in state designated Urban Wildland and High Fire Zones shall be permitted when installed in Class “A” assemblies.
    2. Jurisdictions that prohibit wood roofing materials for application as roof coverings and roof assemblies shall submit documentation for the adoption. Express Terms, statement of reasons and minutes of the action by the adopting authority Health and Safety Code, Section 18959(f).

    SECTION 8-409 — FIRE ALARM SYSTEMS

    Every qualified historical building or property shall be provided with fire alarm systems as required for the use or occupancy by the regular code or other approved alternative.

    SECTION 8-410 — AUTOMATIC SPRINKLER SYSTEMS

    8-410.1 Every qualified historical building or property which cannot be made to conform to the construction requirements specified in the regular code for the occupancy or use, and which constitutes a distinct fire hazard (for definition of “Distinct Hazard,” see Chapter 8-2), shall be deemed to be in compliance if provided with an automatic sprinkler system or a life safety system or other technologies as approved by the enforcing agency. (“Automatic” is defined in the regular code. “Sprinkler System” is defined in this section.)

    8-410.2 When required by the CHBC, an automatic sprinkler system is defined by the following standards as adopted by the State Fire Marshal (for nonhazardous occupancies).

    1. Buildings of four stories or less: NFPA 13R.

    2. For floors above the fourth, NFPA 13.

    3. Buildings with floors above 75 feet, NFPA 13.

    4. When the building is free standing or with property line separation, two floors and 1500 square feet per floor or less, NFPA 13D.

    5. For exterior wall and opening protection. As required by this chapter.

    Exception: When the automatic sprinkler systems are used to reach compliance using this code, in three or more occasions, NFPA 13D standard shall be increased to NFPA 13R standard, or NFPA 13R standard shall be increased to a NFPA 13 standard.

    8-410.3 Automatic sprinkler systems shall not be used to substitute for or act as an alternate to the required number of exits from any facility. (See Chapter 8-5 for exiting requirements.)

    8-410.4 An automatic sprinkler system shall be provided in all detention facilities.

    SECTION 8-411 — OTHER TECHNOLOGIES

    Fire alarm systems, smoke and heat detection systems, occupant notification and annunciation systems, smoke control systems and fire modeling, timed egress analysis and modeling, as well as other engineering methods and technologies may be accepted by the enforcing agency to address areas of nonconformance.

    SECTION 8-412 — HIGH-RISE BUILDINGS

    Qualified historical buildings having floors for human occupancy located more than 75 feet above the lowest floor level having building access shall conform to the provisions of the regular code for existing high-rise buildings as amended by the CHBC.

    8 2025 CALIFORNIA HISTORICAL BUILDING CODE

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    8-5 MEANS OF EGRESS

  • CBC § 2.2. High relevance — show source text

    2.2. Loss of power or circuit continuity to the electronic monitoring device shall initiate a trouble signal. 2.3. The extinguishers shall be installed inside of a building or cabinet in a noncorrosive environment. 2.4. Electronic monitoring devices and supervisory circuits shall be tested every 3 years when extinguisher maintenance is performed. 2.5. A written log of required hydrostatic test dates for extinguishers shall be maintained by the owner to verify that hydrostatic tests are conducted at the frequency required by California Code of Regulations, Title 19, Division 1, Chapter 3. 3. In Group I-3, and in mental health areas of Group I-2, portable fire extinguishers shall be permitted to be located at staff locations.

    [California Code of Regulations, Title 19, Division 1, §565.1(a) through (c)] Classification of Hazards.

    (a) Light (Low) Hazard. Locations where the total amounts of Class A combustible materials, including furnishings, decorations and contents, is of minor quantity. These shall include buildings or rooms occupied as offices, classrooms, churches, assembly halls, etc. This classification anticipates that the majority of the contents are either noncombustible or so arranged that a fire is not likely to spread rapidly. Small amounts of Class B flammables used for duplicating machines, art departments, etc., are included provided that they are kept in closed containers and safely stored.

    (b) Ordinary (Moderate) Hazard. Locations where the total amounts of Class A combustibles and Class B flammables are present in greater amounts than expected under Light (Low) Hazard occupancies. These occupancies could consist of offices, classrooms, mercantile shops and allied storage, light manufacturing, research operations, auto showrooms, parking garages, workshop or support service areas of Light (Low) Hazard occupancies, and warehouses containing Class I or Class II commodities.

    (c) Extra (High) Hazard. Locations where the total amount of Class A combustibles and Class B flammables are present, in storage, production use, and/or finished product over and above those expected and classed as Ordinary (Moderate) Hazards. These occupan- cies could consist of woodworking, vehicle repair, aircraft and boat servicing, individual product display showrooms, product convention center displays, storage and manufacturing processes such as painting, dipping, coating, including flammable liquid handling. Also, included in warehousing of, or in-process storage of other Class I and Class II commodities.

    [California Code of Regulations, Title 19, Division 1, §565.2(a) through (e)] Selection by Hazard.

    (a) Extinguishers shall be selected for the specific class or classes of hazards to be protected in accordance with the following subdivi- sions (b), (c), (d) and (e).

    (b) Extinguishers for protecting Class A hazards shall be selected from the following: Water-type, halogenated agent types, multipur- pose dry chemical and wet chemical type.

    (c) Extinguishers for protection of Class B hazards shall be selected from the following: carbon dioxide, dry chemical types, haloge- nated agent types and water-type and water chemical extinguishers rated for Class B hazards.

    2025 CALIFORNIA FIRE CODE 9-33

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

    FIRE PROTECTION AND LIFE SAFETY SYSTEMS

  • CBC § 1505.7 High relevance — show source text

    [BF] 1505.7 Special purpose roofs. Special purpose wood shingle or wood shake roofing shall conform to the grading and application requirements of Section 1507.8 or 1507.9. In addition, an underlayment of [5] / 8 -inch (15.9 mm) Type X water-resistant gypsum backing board or gypsum sheathing shall be placed under minimum nominal [1] / 2 -inch-thick (12.7 mm) wood structural panel solid sheathing or 1-inch (25 mm) nominal spaced sheathing.

    [BF] 1505.8 Building-integrated photovoltaic (BIPV) systems. BIPV products installed as the roof covering shall be tested, listed and labeled for fire classification in accordance with Section 1505.1.

    [BF] 1505.9 Rooftop mounted photovoltaic (PV) panel systems. Rooftop mounted photovoltaic (PV) panel systems shall be tested, listed and identified with a fire classification in accordance with UL 2703. Listed systems shall be installed in accordance with the manufacturer’s installation instructions and their listing. The fire classification shall comply with Table 1505.1 based on the type of construction of the building.

    [BF] 1505.10 Landscaped and vegetative roofs. Landscaped and vegetative roofs shall comply with Sections 1505.1 and 1507.15. Vegetative roofs shall be installed in accordance with ANSI/SPRI VF-1.

    SECTION 1506—MATERIALS

    1506.1 Scope. The requirements set forth in this section shall apply to the application of roof-covering materials specified herein. Roof coverings shall be applied in accordance with this chapter and the roof covering listing as required by Section 1505. Installation of roof coverings shall comply with the applicable provisions of Section 1507.

    1506.2 Material specifications and physical characteristics. Roof-covering materials shall conform to the applicable standards listed in this chapter.

    15-6 2025 CALIFORNIA BUILDING CODE

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    ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

    1506.3 Product identification. Roof-covering materials shall be delivered in packages bearing the manufacturer’s identifying marks and approved testing agency labels required in accordance with Section 1505. Bulk shipments of materials shall be accompanied with the same information issued in the form of a certificate or on a bill of lading by the manufacturer.

    SECTION 1507—REQUIREMENTS FOR ROOF COVERINGS

    1507.1 Scope. Roof coverings shall be applied in accordance with the applicable provisions of this section and the manufacturer’s installation instructions.

  • CBC § 1.1 High relevance — show source text

    – – – Class I or A, with a 0 25 FSR; Class II or B, with a 26 75 FSR; and Class III or C, with a 76 200 FSR. (Note: Some codes use Roman

    – numerals and others use letters.) The NFPA Life Safety Code also has a Class D (201 500 FSR) and Class E (over 500 FSR) interior finish.

    These classifications are typically used in modern building codes to restrict the rate of fire spread. Only the first three classifications are normally permitted, though not all classes of materials can be used in all places throughout a building. For example, the interior finish of building materials used in exits or in corridors leading to exits is more strictly regulated than materials used within private dwelling units.

    In general, inorganic archaic materials (e.g., bricks or tile) can be expected to be in Class I. Materials of whole wood are mostly Class II. Whole wood is defined as wood used in the same form as sawn from the tree. This is in contrast to the contemporary reconstituted wood products such as plywood, fiberboard, hardboard or particle board. If the organic archaic material is not whole wood, the flame spread classification could be well over 200 and thus would be particularly unsuited for use in exits and other critical locations in a building. Some plywoods and various wood fiberboards have flame spreads over 200. Although they can be treated with fire retardants to reduce their flame spread, it would be advisable to assume that all such products have a flame spread over 200 unless there is information to the contrary.

    Smoke Production

    The evaluation of smoke density is part of the ASTM E84 tunnel test. For the eight species of lumber shown in Table 1.1, the highest levels are 275–305 for Yellow Pine, but most of the others are less smoky than red oak which has an index of 100. The advent of plastics caused substantial increases in the smoke density values measured by the tunnel test. The ensuing limitation of the smoke production for wall and ceiling materials by the model building codes has been a reaction to the introduction of plastic materials. In general, cellulosic materials fall in the 50–300 range of smoke density which is below the general limitation of 450 adopted by many codes.

    RESOURCE A-4 2025 CALIFORNIA EXISTING BUILDING CODE

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

    RESOURCE A—GUIDELINES ON FIRE RATINGS OF ARCHAIC MATERIALS AND ASSEMBLIES

    Degree of Combustibility

    The model building codes tend to define “noncombustibility” on the basis of having passed ASTM E136 or if the material is totally inorganic. The acceptance of gypsum wallboard as noncombustible is based on limiting paper thickness to not over [1] / 8 inch and a 0– 50 flame spread rating by ASTM E84. At times there were provisions to define a Class I or A material (0–25 FSR) as noncombustible, but this is not currently recognized by most model building codes.

    If there is any doubt whether or not an archaic material is noncombustible, it would be appropriate to send out samples for evaluation. If an archaic material is determined to be noncombustible according to ASTM E136, it can be expected that it will not contribute fuel to the fire.

    1.2 COMBUSTIBLE CONSTRUCTION TYPES

Frequently asked questions

Do all roofs in California have to be Class A?

No. The minimum required class depends on the building’s type of construction and other location/occupancy criteria per Table 1505.1; not all buildings need Class A. Check § 1505.1 and Table 1505.1 for the specific minimum. § 1505.1 / Table 1505.1

If I replace more than half my roof in a year, do I have to upgrade?

Yes — outside WUI/FHSZ rules the CBC requires the entire roof covering of a structure where more than 50% of the total roof area is replaced in one year to be a fire‑retardant roof covering at least Class C. § 1505.1.2

What proves a product’s classification?

The product or assembly must be listed and identified as Class A, B or C by an approved testing agency and tested to ASTM E108 or UL 790 when the code requires a classification. Look for the listing label and supporting documentation. § 1505.1

Can I use fire‑retardant‑treated wood shakes?

Yes, but only if they meet the specified test standards (UBC/ASTM E108/UL 790 as applicable), ICC‑ES EG107, and the State Fire Marshal weathering/listing requirements; bundles must bear required labels. § 1505.6

Do photovoltaic panels affect roof classification?

Yes. BIPV products used as roof covering must be tested/listed for fire classification per § 1505.1; rooftop PV systems must comply with UL 2703 and the fire classification requirements in Table 1505.1. § 1505.8, § 1505.9

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