CBC · California Building Code

What exceptions (MCM, EIFS, HPL, foam-plastic) modify combustible-cladding limits?

The CBC’s default limit for combustible exterior wall coverings on many building types is 10% of a wall when separation is ≤5 ft and 40 ft maximum height, but the code explicitly allows certain systems (MCM, EIFS, HPL, and claddings with foam‑plastic) to be treated differently — each in its own section. Those system sections add surface‑burning criteria, ASTM/NFPA testing, drainage and WRB requirements, or alternate area/height rules (for example HPL’s conditional 10% rule when separation ≤5 ft), and assemblies containing foam plastic are governed by Chapter 26 (§2603). For precise application you must read the system section that applies and the Chapter 26 foam‑plastic rules and submit required test reports or documentation to the building official (§1405; §1406; §1407; §1408; §2603) filefilefile.

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Last reviewed: July 5, 2026

What the code requires — 2–4 sentences

The CBC limits combustible exterior wall coverings on Types I–IV construction to 10% of an exterior wall surface where the fire separation distance is 5 feet or less and to a maximum installation height of 40 feet above grade plane, with a short list of specific exceptions for certain cladding systems (MCM, EIFS, HPL, and exterior wall coverings containing foam-plastic insulation) that are addressed in their own sections: §1405.1 (exceptions) . Ignition-resistance testing for combustible coverings is required by NFPA 268 where §1405.1.1 applies , and several of the exception sections add system tests, surface-burning limits, or NFPA 285/full-scale test requirements that change how the 10%/40-foot limits are applied (see §1406, §1407, §1408 and cross-references to §2603) .

Requirements in detail

Overview: the basic limit and the exception framework

  • Basic limits for combustible exterior wall coverings on Types I–IV construction: not more than 10% of an exterior wall surface when fire separation distance ≤ 5 ft; limited to 40 ft in height above grade plane (§1405.1.1, items 1–2) .
  • Exceptions to those numeric limits are explicitly listed in §1405.1.1 and refer to the system-specific sections:
    • Metal composite material (MCM) systems — §1406
    • Exterior insulation and finish systems (EIFS) — §1407
    • High‑pressure decorative exterior‑grade compact laminates (HPL) — §1408
    • Exterior wall coverings containing foam‑plastic insulation — §2603 (cross-referenced)

Decision-relevant numeric limits and test requirements

Item Value / limit When it matters Code Reference
Max combustible cladding height (default) 40 ft above grade plane Types I–IV unless exception applies §1405.1.1 (2)
Max combustible cladding area when separation ≤ 5 ft 10% of exterior wall surface Types I–IV (default) §1405.1.1 (1)
Ignition-resistance test required NFPA 268 When §1405.1.1 permits combustible coverings; sustained flaming prohibited at ≤5 ft §1405.1.1.1 & §1405.1.1.1.1; Table 1405.1.1.1.2 (minimum fire separation vs. radiant heat)
MCM surface-burning (general) Flame spread index ≤ 75; smoke ≤ 450 (ASTM E84/UL723) General requirement for MCM systems (§1406.9) §1406.9
MCM installations > 40 ft Flame spread index ≤ 25; smoke ≤ 450; thermal barrier separation required (½" gypsum or NFPA 275 test) MCM on Types I–IV above 40 ft (§1406.10.1–.10.2) §1406.10.1–§1406.10.2
MCM NFPA 285/full-scale NFPA 285 required for systems per §1406.10.3 When full‑scale acceptance criteria are used §1406.10.3
EIFS performance Must meet ASTM E2568; EIFS with drainage must meet ASTM E2273 drainage efficiency and W‑R barrier per §1407.4.1/.1.1 EIFS materials and drainage details; EIFS any height must comply with §2603.5 §1407.2; §1407.4.1; §1407.4.1.1; §1407.5
HPL surface-burning Flame spread index ≤ 75; smoke ≤ 450 (ASTM E84/UL723) General for HPL systems (§1408.9) §1408.9
HPL alternate (up to 40 ft) Installations ≤ 40 ft allowed if: fire separation ≤ 5 ft → HPL ≤ 10% of wall; fire separation > 5 ft → no area limit §1408.11.1 (.1.1 and .1.2) §1408.11.1.1–§1408.11.1.2
HPL / MCM containing foam insulation Must comply with §2603 for foam-plastic requirements When foam-plastic insulation is included §1406.12; §1408.13
Full-scale testing (HPL) NFPA 285 testing and acceptance criteria required for HPL systems where specified (§1408.10.4) Where full‑scale behavior is used to justify exceptions §1408.10.4

Notes on the table: the “default” 10% / 40 ft limits in §1405 are the baseline; each system section (§1406, §1407, §1408) modifies how those limits apply by adding surface-burning requirements, system tests (NFPA 285), drainage and WRB requirements, or explicit alternate area/height rules (HPL) .

How each exception changes the limits (concise)

  • MCM (§1406): MCM is specifically regulated — it must meet surface-burning limits and, for taller installations (>40 ft), stricter ASTM/thermal‑barrier or full‑scale NFPA 285 test criteria apply; an administrative exception exists when MCM is installed on the outer surface of a fire‑resistance‑rated wall without penetrating the rated assembly (§1406.8 exception) .
  • EIFS (§1407): EIFS must meet performance standard ASTM E2568; EIFS with drainage must meet drainage efficiency and specific WRB requirements, and exterior wall assemblies that include EIFS must also meet the foam‑plastic / exterior‑wall assembly rules at §2603.5 (EIFS is therefore permitted but constrained by §2603 where insulation is foam) .
  • HPL (§1408): HPL is allowed and has an explicit alternate path for installations up to 40 ft: if fire separation ≤ 5 ft, HPL area is limited to 10% of wall; if separation > 5 ft, area is not limited. HPL also has surface-burning limits and NFPA 285/full‑scale testing provisions in the section, and HPL systems that include foam plastic must comply with §2603 (§1408.11.1; §1408.9; §1408.10.4; §1408.13) .
  • Foam‑plastic insulation (§2603): Any exterior wall covering that contains foam‑plastic insulation is addressed by §2603; many of the system exceptions require compliance with §2603 for assemblies with foam plastic (cross-referenced by §1405.1.1 exceptions, §1406.12, §1407.5, §1408.13) . The specific detailed requirements in §2603 (for example, allowable foam types, thickness limits, testing, and NFPA 285 applicability) are contained in Chapter 26; the retrieved files reference §2603 but the full §2603 text was not included in the retrieved excerpts and therefore specific clause-level values from §2603 are not quoted here.

Exceptions & special cases

  • Thermal‑barrier / nonpenetration exception: MCM and HPL systems that do not contain foam plastic and are installed on the outside of a fire‑resistance‑rated exterior wall such that attachments do not penetrate the entire rated assembly are exempt from some of the section requirements (§1406 exception; §1408 exception) .
  • Full‑scale (NFPA 285 / NFPA 286 / UL tests): both MCM and HPL sections allow full‑scale testing (NFPA 285 or other listed acceptance criteria) as an alternate compliance path for assemblies where surface‑burning tests alone are insufficient or where installations exceed 40 ft (§1406.10.3; §1408.10.4) .
  • EIFS with drainage: EIFS with drainage is required to meet ASTM E2273 drainage efficiency and specific WRB requirements where required (e.g., framed walls of Type V R occupancies) and EIFS assemblies at any height must comply with §2603.5 for foam-plastic rules (§1407.4.1; §1407.4.1.1; §1407.5) .
  • Fire separation / radiant heat: NFPA 268-based ignition criteria and the Table 1405.1.1.1.2 fire separation / incident radiant flux table control what separation distances (and therefore area limits) are acceptable for combustible exterior coverings; where separation ≤ 5 ft sustained flaming is prohibited (§1405.1.1.1 and §1405.1.1.1.1) .
  • Furred cavities and fireblocking: if a combustible exterior covering is furred out and creates a concealed space, the CBC limits the back gap to 1 5/8" unless the concealed space is not required to be fireblocked by §718; otherwise the space must be fireblocked (§1405.1.3) .

Common mistakes

  • Assuming the §1405 numeric limits (10% / 40 ft) never apply once a system-specific section is referenced — many exceptions change only certain parameters (surface-burning, tests) and do not automatically remove area/height controls unless the system section explicitly does so (for example, HPL up to 40 ft has its own alternate area rule) (§1405.1.1; §1408.11.1) file.
  • Overlooking foam‑plastic cross‑references: if a system contains foam insulation, §2603 applies and imposes additional restrictions; designers sometimes apply MCM/HPL/EIFS rules without checking §2603 obligations (§1406.12; §1408.13; §1407.5) filefile.
  • Misreading HPL alternate rules: HPL has a conditional allowance up to 40 ft with differing area limits depending on fire separation (≤5 ft → 10% area; >5 ft → no area limit). Don’t assume “up to 40 ft” always means unlimited area (§1408.11.1.1–.2) .
  • Forgetting required tests and documentation: full‑scale NFPA 285/NFPA 286/UL tests, ASTM performance tests and manufacturer instructions or labeling are required or expected for many of these systems (§1406.10.3; §1407.2; §1407.6; §1408.10.4; labeling §1406.13 / §1408.14) filefile.

Worked example — concrete scenario

Scenario: A designer proposes HPL cladding on a Type III (noncombustible structural) office building. The cladding will be installed at 30 feet above grade on an exterior wall where the nearest property line/adjacent building results in a fire separation distance of 4 feet (≤ 5 ft). The HPL will cover 12% of that wall surface.

Code application:

  1. Baseline: combustible exterior wall coverings are limited to 10% of the exterior wall when fire separation ≤ 5 ft (§1405.1.1 (1)) .
  2. HPL alternate allowance: §1408.11.1 permits HPL installations up to 40 ft, but §1408.11.1.1 states where fire separation is 5 ft or less the area of HPL shall not exceed 10% of the exterior wall surface (§1408.11.1.1) .
  3. Outcome: Because the wall separation is 4 ft (≤5 ft), the proposed 12% coverage exceeds the HPL area limit and is not code‑compliant as proposed. Remedies include reducing HPL coverage to ≤10%, increasing the fire separation to >5 ft (if physically possible), or demonstrating compliance by another allowed means in §1408 (for example, showing additional testing/assembly features per §1408; consult the building official) .

Related provisions

  • Combustible exterior wall coverings — §1405.1
  • Ignition-resistance / NFPA 268 and separation table — §1405.1.1.1; §1405.1.1.1.1; Table 1405.1.1.1.2
  • Fireblocking for furred out coverings — §1405.1.3
  • Metal composite materials (MCM) general and testing — §1406 (notably §1406.9; §1406.10.1–.10.3; §1406.12) file
  • EIFS performance and drainage; EIFS cross‑reference to §2603 — §1407.2; §1407.4.1; §1407.5; §1407.7
  • HPL testing and alternate area/height rules — §1408 (notably §1408.9; §1408.10.4; §1408.11.1; §1408.13) file
  • Foam‑plastic insulation and exterior wall assemblies (Chapter 26) — §2603 (cross‑referenced from §§1405, 1406, 1407, 1408) — note: detailed text of §2603 was not included in the retrieved excerpts; consult Chapter 26 for full requirements file

Code references

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

  • CBC § 2303.2 High relevance — show source text
    1. Combustible exterior wall coverings shall be limited to 40 feet (12 192 mm) in height above grade plane. Exceptions:
    2. Metal composite material (MCM) systems complying with Section 1406.
    3. Exterior insulation and finish systems (EIFS) complying with Section 1407.
    4. High-pressure decorative exterior-grade compact laminate (HPL) systems complying with Section 1408.
    5. Exterior wall coverings containing foam plastic insulation complying with Section 2603.
    6. Combustible exterior wall coverings constructed of fire-retardant-treated wood complying with Section 2303.2 for exterior installation shall not be limited in wall surface area where the fire separation distance is 5 feet (1524 mm) or less and shall be permitted up to 60 feet (18 288 mm) in height above grade plane regardless of the fire separation distance.
    7. Wood veneers shall comply with Section 1404.6.

    1405.1.1.1 Ignition resistance. Where permitted by Section 1405.1.1, combustible exterior wall coverings shall be tested in accordance with NFPA 268.

    Exceptions:

    1. Wood or wood-based products.
    2. Other combustible materials covered with an exterior weather covering, other than vinyl sidings, included in and complying with the thickness requirements of Table 1404.2.
    3. Aluminum having a minimum thickness of 0.019 inch (0.48 mm).

    1405.1.1.1.1 Fire separation 5 feet or less. Where installed on exterior walls having a fire separation distance of 5 feet (1524 mm) or less, combustible exterior wall coverings shall not exhibit sustained flaming as defined in NFPA 268.

    1405.1.1.1.2 Fire separation greater than 5 feet. For fire separation distances greater than 5 feet (1524 mm), any exterior wall covering shall be permitted that has been exposed to a reduced level of incident radiant heat flux in accordance with the NFPA 268 test method without exhibiting sustained flaming. The minimum fire separation distance required for the exterior wall covering shall be determined from Table 1405.1.1.1.2 based on the maximum tolerable level of incident radiant heat flux that does not cause sustained flaming of the exterior wall covering.

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    EXTERIOR WALLS

  • CBC § 1404.19 High relevance — show source text

    [BS] 1404.19 Fiber-mat reinforced cementitious backer units. Fiber-mat reinforced cementitious backer units shall be permitted on exterior walls and shall meet the requirements of Section 1404.19.1.

    [BS] 1404.19.1 Installation. Installation of fiber-mat reinforced cementitious backer units used as an exterior substrate for the application of exterior finish materials shall be in accordance with backer unit manufacturer’s installation instructions. Panels shall be installed using corrosion-resistant fasteners. Finish materials shall be installed in accordance with approved finish material manufacturer’s instructions.

    SECTION 1405—COMBUSTIBLE MATERIALS ON THE EXTERIOR SIDE OF EXTERIOR WALLS

    1405.1 Combustible exterior wall coverings. Combustible exterior wall coverings shall comply with this section.

    Exception: Plastics complying with Chapter 26.

    1405.1.1 Types I, II, III and IV-HT construction. On buildings of Types I, II, III and IV-HT construction, exterior wall coverings shall be permitted to be constructed of combustible materials, complying with the following limitations:

    1. Combustible exterior wall coverings shall not exceed 10 percent of an exterior wall surface area where the fire separation distance is 5 feet (1524 mm) or less.
    2. Combustible exterior wall coverings shall be limited to 40 feet (12 192 mm) in height above grade plane. Exceptions:
    3. Metal composite material (MCM) systems complying with Section 1406.
    4. Exterior insulation and finish systems (EIFS) complying with Section 1407.
    5. High-pressure decorative exterior-grade compact laminate (HPL) systems complying with Section 1408.
    6. Exterior wall coverings containing foam plastic insulation complying with Section 2603.
    7. Combustible exterior wall coverings constructed of fire-retardant-treated wood complying with Section 2303.2 for exterior installation shall not be limited in wall surface area where the fire separation distance is 5 feet (1524 mm) or less and shall be permitted up to 60 feet (18 288 mm) in height above grade plane regardless of the fire separation distance.
    8. Wood veneers shall comply with Section 1404.6.

    1405.1.1.1 Ignition resistance. Where permitted by Section 1405.1.1, combustible exterior wall coverings shall be tested in accordance with NFPA 268.

    Exceptions:

    1. Wood or wood-based products.
    2. Other combustible materials covered with an exterior weather covering, other than vinyl sidings, included in and complying with the thickness requirements of Table 1404.2.
    3. Aluminum having a minimum thickness of 0.019 inch (0.48 mm).

    1405.1.1.1.1 Fire separation 5 feet or less. Where installed on exterior walls having a fire separation distance of 5 feet (1524 mm) or less, combustible exterior wall coverings shall not exhibit sustained flaming as defined in NFPA 268.

  • CBC § 1402.4 High relevance — show source text

    1402.4 Fire resistance. Exterior walls shall be fire-resistance rated as required by other sections of this code with opening protection as required by Chapter 7.

    1402.5 Vertical and lateral flame propagation. Exterior walls on buildings of Type I, II, III and IV construction that contain a combustible exterior wall covering, combustible insulation or a combustible water-resistive barrier shall comply with Sections 1402.5.1 through 1402.5.5, as applicable. Where compliance with NFPA 285 and associated acceptance criteria is required in Sections 1402.5.1 through 1402.5.5, the exterior wall assembly shall be tested in accordance with and comply with the acceptance criteria of NFPA 285.

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    1402.5.1 Combustible water-resistive barrier. Exterior walls containing a combustible water-resistive barrier shall comply with Section 1402.6.

    1402.5.2 Metal composite material (MCM). Exterior walls containing metal composite material (MCM) systems shall comply with Section 1406.

    1402.5.3 Exterior insulation and finish system (EIFS). Exterior walls containing an exterior insulation and finish system (EIFS) shall comply with Section 1407.

    1402.5.4 High-pressure decorative exterior-grade compact laminate (HPL) system. Exterior walls containing a high-pressure decorative exterior-grade compact laminate (HPL) system shall comply with Section 1408.

    1402.5.5 Foam plastic insulation. Exterior walls containing foam plastic insulation shall comply with Section 2603.

    1402.6 Water-resistive barriers. Exterior walls on buildings of Type I, II, III or IV construction that are greater than 40 feet (12 192 mm) in height above grade plane and contain a combustible water-resistive barrier shall be tested in accordance with and comply with the acceptance criteria of NFPA 285.Combustibility shall be determined in accordance with Section 703.3. For the purposes of this section, fenestration products, flashing of fenestration products and water-resistive-barrier flashing and accessories at other locations, including through wall flashings, shall not be considered part of the water-resistive barrier.

    Exceptions:

    1. Exterior walls in which the water-resistive barrier is the only combustible component and the exterior wall has an exterior wall covering of brick, concrete, stone, terra cotta, stucco or steel with minimum thicknesses in accordance with Table 1404.2.

    2. Exterior walls in which the water-resistive barrier is the only combustible component and the water-resistive barrier complies with the following: 2.1 A peak heat release rate of less than 150 kW/m [2], a total heat release of less than 20 MJ/m [2] and an effective heat of combustion of less than 18 MJ/kg when tested on specimens at the thickness intended for use, in accordance with ASTM E1354, in the horizontal orientation and at an incident radiant heat flux of 50 kW/m [2] .

    2.2 A flame spread index of 25 or less and a smoke-developed index of 450 or less as determined in accordance with ASTM E84 or UL 723, with test specimen preparation and mounting in accordance with ASTM E2404.

  • CBC § 1406.4 High relevance — show source text

    [BS] 1406.4 Structural design. MCM systems shall be designed and constructed to resist wind loads as required by Chapter 16 for components and cladding.

    1406.5 Approval. Results of approved tests or an engineering analysis shall be submitted to the building official to verify compliance with the requirements of Chapter 16 for wind loads.

    1406.6 Weather resistance. MCM systems shall comply with Section 1402 and shall be designed and constructed to resist wind and rain in accordance with this section and the manufacturer’s installation instructions.

    1406.7 Durability. MCM systems shall be constructed of approved materials that maintain the performance characteristics required in Section 1406 for the duration of use.

    1406.8 Fire-resistance rating. Where MCM systems are used on exterior walls required to have a fire-resistance rating in accordance with Section 705, evidence shall be submitted to the building official that the required fire-resistance rating is maintained.

    Exception: MCM systems that are part of an exterior wall assembly not containing foam plastic insulation and are installed on the outer surface of a fire-resistance-rated exterior wall in a manner such that the attachments do not penetrate through the entire exterior wall assembly, shall not be required to comply with this section.

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    1406.9 Surface-burning characteristics. Unless otherwise specified, MCM shall have a flame spread index of 75 or less and a smokedeveloped index of 450 or less when tested in the maximum thickness intended for use in accordance with ASTM E84 or UL 723.

    1406.10 Types I, II, III and IV construction. Where installed on buildings of Types I, II, III and IV construction, metal composite material (MCM) shall comply with Sections 1406.10.1 and 1406.10.2 for installations up to 40 feet (12 192 mm) above grade plane. Where installed on buildings of Type I, II, III and IV construction, MCMs and MCM systems shall comply with Sections 1406.10.1 through 1406.10.3, for installations greater than 40 feet (12 192 mm) above grade plane.

    1406.10.1 Surface-burning characteristics. MCM shall have a flame spread index of not more than 25 and a smoke-developed index of not more than 450 when tested in the maximum thickness intended for use in accordance with ASTM E84 or UL 723.

    1406.10.2 Thermal barriers. MCM shall be separated from the interior of a building by an approved thermal barrier consisting of 1 / 2 -inch (12.7 mm) gypsum wallboard or material that is tested in accordance with and meets the acceptance criteria of both the Temperature Transmission Fire Test and the Integrity Fire Test of NFPA 275.

    Exceptions:

    1. The MCM system is specifically approved based on tests conducted in accordance with NFPA 286 and with the acceptance criteria of Section 803.1.1.1, UL 1040 or UL 1715. Such testing shall be performed with the MCM in the maximum thickness intended for use. The MCM system shall include seams, joints and other typical details used in the installation and shall be tested in the manner intended for use.

    2. The MCM is used as elements of balconies and similar projections, architectural trim or embellishments.

  • CBC § 2607.4 High relevance — show source text

    Exceptions:

    1. In structures provided with approved flame barriers extending 30 inches (760 mm) beyond the exterior wall in the plane of the floor, a vertical separation is not required at the floor except that provided by the vertical thickness of the flame barrier projection.
    2. Veneers of approved weather-resistant light-transmitting plastics used as exterior siding in buildings of Type V construction in compliance with Section 1405.
    3. The area of light-transmitting plastic wall panels in exterior walls of greenhouses shall be exempt from the area limitations of Table 2607.4 but shall be limited as required for unprotected openings in accordance with Section 705.9.
    TABLE 2607.4—AREA LIMITATION AND SEPARATION REQUIREMENTS FOR LIGHT-TRANSMITTING PLASTIC WALL PANELSa Col2 Col3 Col4 Col5 Col6
    FIRE
    SEPARATION
    DISTANCE
    (feet)    		 CLASS OF
    PLASTIC    		 MAXIMUM
    PERCENTAGE AREA
    OF EXTERIOR WALL IN
    PLASTIC WALL
    PANELS    		 MAXIMUM SINGLE
    AREA OF PLASTIC
    WALL PANELS
    (square feet)    		 MINIMUM SEPARATION OF PLASTIC WALL PANELS
    (feet)    		 MINIMUM SEPARATION OF PLASTIC WALL PANELS
    (feet)
    FIRE
    SEPARATION
    DISTANCE
    (feet)    		 CLASS OF
    PLASTIC    		 MAXIMUM
    PERCENTAGE AREA
    OF EXTERIOR WALL IN
    PLASTIC WALL
    PANELS    		 MAXIMUM SINGLE
    AREA OF PLASTIC
    WALL PANELS
    (square feet)    		 Vertical Horizontal
    Less than 6 — Not Permitted Not Permitted — —
    6 or more but less
    than 11    		 CC1 10 50 8 4
    6 or more but less
    than 11    		 CC2 Not Permitted Not Permitted — —
    11 or more but less
    than or equal to 30    		 CC1 25 90 6 4
    11 or more but less
    than or equal to 30    		 CC2 15 70 8 4
    Over 30 CC1 50 Not Limited 3b 0
    Over 30 CC2 50 100 6b 3
    For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2.
    a. For combinations of plastic glazing and plastic wall panel areas permitted, see Section 2607.6.
    b. For reductions in vertical separation allowed, see Section 2607.4.    		 For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2.
    a. For combinations of plastic glazing and plastic wall panel areas permitted, see Section 2607.6.
    b.
  • CBC § 1405.1.3 High relevance — show source text

    1405.1.3 Fireblocking. Where the combustible exterior wall covering is furred out from the exterior wall and forms a solid surface, the distance between the back of the exterior wall covering and the exterior wall shall not exceed 1 [5] / 8 inches (41 mm). The concealed space thereby created shall be fireblocked in accordance with Section 718. Exception: The distance between the back of the exterior wall covering and the exterior wall shall be permitted to exceed 1 [5] / 8 inches (41 mm) where the concealed space is not required to be fireblocked by Section 718.

    SECTION 1406—METAL COMPOSITE MATERIAL (MCM)

    1406.1 General. The provisions of this section shall govern the materials, construction and quality of metal composite material (MCM) for use as exterior wall coverings in addition to other applicable requirements of Chapters 14 and 16.

    1406.2 Exterior wall covering. MCM used as exterior wall covering or as elements of balconies and similar projections and bay and oriel windows to provide cladding or weather resistance shall comply with Sections 1406.4 through 1406.13.

    1406.3 Architectural trim and embellishments. MCM used as architectural trim or embellishments shall comply with Sections 1406.7 through 1406.13.

    [BS] 1406.4 Structural design. MCM systems shall be designed and constructed to resist wind loads as required by Chapter 16 for components and cladding.

    1406.5 Approval. Results of approved tests or an engineering analysis shall be submitted to the building official to verify compliance with the requirements of Chapter 16 for wind loads.

    1406.6 Weather resistance. MCM systems shall comply with Section 1402 and shall be designed and constructed to resist wind and rain in accordance with this section and the manufacturer’s installation instructions.

    1406.7 Durability. MCM systems shall be constructed of approved materials that maintain the performance characteristics required in Section 1406 for the duration of use.

    1406.8 Fire-resistance rating. Where MCM systems are used on exterior walls required to have a fire-resistance rating in accordance with Section 705, evidence shall be submitted to the building official that the required fire-resistance rating is maintained.

    Exception: MCM systems that are part of an exterior wall assembly not containing foam plastic insulation and are installed on the outer surface of a fire-resistance-rated exterior wall in a manner such that the attachments do not penetrate through the entire exterior wall assembly, shall not be required to comply with this section.

    2025 CALIFORNIA BUILDING CODE 14-17

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    1406.9 Surface-burning characteristics. Unless otherwise specified, MCM shall have a flame spread index of 75 or less and a smokedeveloped index of 450 or less when tested in the maximum thickness intended for use in accordance with ASTM E84 or UL 723.

  • CBC § 1407.4.1 High relevance — show source text

    1407.4.1 EIFS with drainage. EIFS with drainage shall have an average minimum drainage efficiency of 90 percent when tested in accordance the requirements of ASTM E2273 and is required on framed walls of Type V construction, Group R1, R2, R3 and R4 occupancies.

    1407.4.1.1 Water-resistive barrier. For EIFS with drainage, the water-resistive barrier shall comply with Section 1403.2 or ASTM E2570.

    1407.5 Exterior walls of buildings of any height. Exterior wall assemblies containing an EIFS exterior wall covering shall comply with Section 2603.5.

    1407.6 Installation. Installation of the EIFS and EIFS with drainage shall be in accordance with the EIFS manufacturer’s instructions.

    1407.7 Special inspections. EIFS installations shall comply with the provisions of Sections 1704.2 and 1705.17.

    SECTION 1408—HIGH-PRESSURE DECORATIVE EXTERIOR-GRADE COMPACT LAMINATES (HPL)

    1408.1 General. The provisions of this section shall govern the materials, construction and quality of High-Pressure Decorative ExteriorGrade Compact Laminates (HPL) for use as exterior wall coverings in addition to other applicable requirements of Chapters 14 and 16.

    1408.2 Exterior wall covering. HPL used as exterior wall covering or as elements of balconies and similar projections and bay and oriel windows to provide cladding or weather resistance shall comply with Sections 1408.4 through 1408.14.

    1408.3 Architectural trim and embellishments. HPL used as architectural trim or embellishments shall comply with Sections 1408.7 through 1408.14.

    [BS] 1408.4 Structural design. HPL systems shall be designed and constructed to resist wind loads as required by Chapter 16 for components and cladding.

    1408.5 Approval. Results of approved tests or an engineering analysis shall be submitted to the building official to verify compliance with the requirements of Chapter 16 for wind loads.

    1408.6 Weather resistance. HPL systems shall comply with Section 1402 and shall be designed and constructed to resist wind and rain in accordance with this section and the manufacturer’s instructions.

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    1408.7 Durability. HPL systems shall be constructed of approved materials that maintain the performance characteristics required in Section 1408 for the duration of use.

    1408.8 Fire-resistance rating. Where HPL systems are used on exterior walls required to have a fire-resistance rating in accordance with Section 705, evidence shall be submitted to the building official that the required fire-resistance rating is maintained.

    Exception: HPL systems not containing foam plastic insulation, which are installed on the outer surface of a fire-resistance-rated exterior wall in a manner such that the attachments do not penetrate through the entire exterior wall assembly, shall not be required to comply with this section.

    1408.9 Surface-burning characteristics. Unless otherwise specified, HPL shall have a flame spread index of 75 or less and a smokedeveloped index of 450 or less when tested in the minimum and maximum thicknesses intended for use in accordance with ASTM E84 or UL 723.

  • CBC § 1406.10.3 High relevance — show source text
    1. The MCM is used as elements of balconies and similar projections, architectural trim or embellishments.

    1406.10.3 Full-scale tests. The MCM system shall be tested in accordance with, and comply with, the acceptance criteria of NFPA 285. Such testing shall be performed on the MCM system with the MCM in the maximum thickness intended for use.

    1406.11 Type V construction. MCM shall be permitted to be installed on buildings of Type V construction.

    1406.12 Foam plastic insulation. Where MCM systems are included in an exterior wall assembly containing foam plastic insulation, the exterior wall assembly shall also comply with the requirements of Section 2603.

    1406.13 Labeling. MCM shall be labeled in accordance with Section 1703.5.

    SECTION 1407—EXTERIOR INSULATION AND FINISH SYSTEMS (EIFS)

    1407.1 General. The provisions of this section shall govern the materials, construction and quality of exterior insulation and finish systems (EIFS) for use as exterior wall coverings in addition to other applicable requirements of Chapters 7, 14, 16, 17 and 26.

    1407.2 Performance characteristics. EIFS shall be constructed such that it meets the performance characteristics required in ASTM E2568.

    [BS] 1407.3 Structural design. The underlying structural framing and substrate shall be designed and constructed to resist loads as required by Chapter 16.

    1407.4 Weather resistance. EIFS shall comply with Section 1402 and shall be designed and constructed to resist wind and rain in accordance with this section and the manufacturer’s application instructions.

    1407.4.1 EIFS with drainage. EIFS with drainage shall have an average minimum drainage efficiency of 90 percent when tested in accordance the requirements of ASTM E2273 and is required on framed walls of Type V construction, Group R1, R2, R3 and R4 occupancies.

    1407.4.1.1 Water-resistive barrier. For EIFS with drainage, the water-resistive barrier shall comply with Section 1403.2 or ASTM E2570.

    1407.5 Exterior walls of buildings of any height. Exterior wall assemblies containing an EIFS exterior wall covering shall comply with Section 2603.5.

    1407.6 Installation. Installation of the EIFS and EIFS with drainage shall be in accordance with the EIFS manufacturer’s instructions.

    1407.7 Special inspections. EIFS installations shall comply with the provisions of Sections 1704.2 and 1705.17.

    SECTION 1408—HIGH-PRESSURE DECORATIVE EXTERIOR-GRADE COMPACT LAMINATES (HPL)

    1408.1 General. The provisions of this section shall govern the materials, construction and quality of High-Pressure Decorative ExteriorGrade Compact Laminates (HPL) for use as exterior wall coverings in addition to other applicable requirements of Chapters 14 and 16.

    1408.2 Exterior wall covering. HPL used as exterior wall covering or as elements of balconies and similar projections and bay and oriel windows to provide cladding or weather resistance shall comply with Sections 1408.4 through 1408.14.

    1408.3 Architectural trim and embellishments. HPL used as architectural trim or embellishments shall comply with Sections 1408.7 through 1408.14.

  • CBC § 2.3. High relevance — show source text

    1 to 2.3._ Exception: The gap-to-side plate thickness ratio shall be permitted to be modified for moment connections with unequal beam sizes on opposite sides of the column or when orthogonal beams acting as drag connections frame into the side plate. 8. Demand critical fillet welds {2}, {5}, {5a} and {7} shall have Magnetic Particle Testing (MT) in accordance with AWS D1.1 for procedure, technique and acceptance. Inspect the beginning and end of these welds for a 6-inch length, plus any location along the length of the weld where a start and restart is visually noted for a distance of 6 inches on either side of the start/stop location.

    2202.4.3 Modifications to AISC 358 Chapter 11 Bolted Moment Connection The bolted sideplate steel moment connection shall be permitted, provided: 1. The beams shall consist of either rolled or built-up wide flange sections. Columns shall consist of rolled or built-up wide flange sections or noncomposite built-up box or HSS with a minimum wall thickness of [3] / 4 inch (19 mm), or satisfy the requirements of width-to-thickness ratios of highly ductile members in AISC 341-16. 2. The biaxial dual-strong axis and column minor axis configurations of the moment connection shall be considered as an alternative system. 3. For SMF and IMF systems, on the sideplate standard or configuration A the U-shaped cover plates shall be used with the k dimension extension. The k dimension extension length is defined as beam depth d b /6, rounded to the nearest [1] / 2 inch (12.7 mm).

    4. The hinge-to-hinge span to beam depth, L h /d, shall be greater than or equal to 4.5. 5. The width-to-thickness ratios for beam flanges shall not be less than 3.5. Exception: For width-to-thickness ratios less than 3.5 the C pr shall be calculated in accordance with that for welded side- plate connections but in no case shall the width-to-thickness ratio be less than 3.0. 6. The minimum bolt-to-bolt spacing shall not be less than 3 bolt diameters. 7. The extension of the side plates beyond the face of the column shall be within the range of 0.65d to 1.5d. 8. The gap-to-side plate thickness ratio shall range from 2.1 to 2.3.

    Exception: The gap-to-side plate thickness ratio shall be permitted to be modified for moment connections with unequal beam sizes on opposite sides of the column or when orthogonal beams acting as drag connections frame into the side plate. 9. Demand Critical fillet welds {2}, {5}, {5a} and {8} shall have Magnetic Particle Testing (MT) in accordance with AWS D1.1 for procedure, technique and acceptance. Inspect the beginning and end of these welds for a 6-inch (152 mm) length, plus any location along the length of the weld where a start and restart is visually noted for a distance of 6 inches (152 mm) on either side of the start/stop location. 10. The connection specific factor to account for peak connection strength, C pr _, shall be between 1.15 and 1.35.

  • CBC § 1404.6. High relevance — show source text
    1. Wood veneers shall comply with Section 1404.6.

    1405.1.1.1 Ignition resistance. Where permitted by Section 1405.1.1, combustible exterior wall coverings shall be tested in accordance with NFPA 268.

    Exceptions:

    1. Wood or wood-based products.
    2. Other combustible materials covered with an exterior weather covering, other than vinyl sidings, included in and complying with the thickness requirements of Table 1404.2.
    3. Aluminum having a minimum thickness of 0.019 inch (0.48 mm).

    1405.1.1.1.1 Fire separation 5 feet or less. Where installed on exterior walls having a fire separation distance of 5 feet (1524 mm) or less, combustible exterior wall coverings shall not exhibit sustained flaming as defined in NFPA 268.

    1405.1.1.1.2 Fire separation greater than 5 feet. For fire separation distances greater than 5 feet (1524 mm), any exterior wall covering shall be permitted that has been exposed to a reduced level of incident radiant heat flux in accordance with the NFPA 268 test method without exhibiting sustained flaming. The minimum fire separation distance required for the exterior wall covering shall be determined from Table 1405.1.1.1.2 based on the maximum tolerable level of incident radiant heat flux that does not cause sustained flaming of the exterior wall covering.

    14-16 2025 CALIFORNIA BUILDING CODE

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

    EXTERIOR WALLS

    TABLE 1405.1.1.1.2—MINIMUM FIRE SEPARATION FOR COMBUSTIBLE EXTERIOR WALL COVERINGS Col2
    FIRE SEPARATION DISTANCE (feet) TOLERABLE LEVEL INCIDENT RADIANT HEAT ENERGY (kW/m2)
    5 12.5
    6 11.8
    7 11.0
    8 10.3
    9 9.6
    10 8.9
    11 8.3
    12 7.7
    13 7.2
    14 6.7
    15 6.3
    16 5.9
    17 5.5
    18 5.2
    19 4.9
    20 4.6
    21 4.4
    22 4.1
    23 3.9
    24 3.7
    25 3.5
    For SI: 1 foot = 304.8 mm, 1 Btu/H2 × °F = 0.0057 kW/m2 × K. For SI: 1 foot = 304.8 mm, 1 Btu/H2 × °F = 0.0057 kW/m2 × K.

    1405.1.2 Location. Combustible exterior wall coverings located along the top of exterior walls shall be completely backed up by the exterior wall and shall not extend over or above the top of the exterior wall.

  • CBC § 1.15 High relevance — show source text

    Exception: The gap-to-side plate thickness ratio shall be permitted to be modified for moment connections with unequal beam sizes on opposite sides of the column or when orthogonal beams acting as drag connections frame into the side plate. 9. Demand Critical fillet welds {2}, {5}, {5a} and {8} shall have Magnetic Particle Testing (MT) in accordance with AWS D1.1 for procedure, technique and acceptance. Inspect the beginning and end of these welds for a 6-inch (152 mm) length, plus any location along the length of the weld where a start and restart is visually noted for a distance of 6 inches (152 mm) on either side of the start/stop location. 10. The connection specific factor to account for peak connection strength, C pr , shall be between 1.15 and 1.35. Calculations shall be submitted to OSHPD for review and approval. 11. For in-plane collectors transferring axial loads into the sideplate connection, coordination between sideplate and the regis- tered design professional in responsible charge will be required to confirm the collector connection is sufficient to transfer the load into the moment frame system. This requirement shall be satisfied by designing the sideplate connections in the first bay of a multi-bay sideplate moment frame or an end bay to have a minimum connection capacity, including combined shear (V u + V g ) and moment (M pr ) demands, of at least 1.2 times the M pr at the plastic hinge location when the axial load, as determined by ASCE 7, Section 12.10.2.1 without Ω o , exceeds 0.1 F y A g of the sideplate beam. 12. A complete frame analysis for gravity and design wind loading using LRFD load combinations in Section 1605A.1 shall be performed including Demand/Capacity Ratios. Frame beam member nominal moment strengths (M n ) used for gravity and design wind loading for the bolted sideplate connection using Class A or Class B faying surfaces shall be taken as 0.80 F y Z for frame beams up to 300 plf and 0.60 F y Z for frame beams greater than 300 plf. 13. For moment frame beams with maximum beam shear greater than 90 percent of the vertical bolt shear capacity, a second- ary check is to be provided to confirm the vertical bolt shear capacities are sufficient. 14. Bolted sideplate connections used on heavy-shallow frame beams for beams greater than 200 plf and shallower than 24 inches (610 mm) in depth shall be considered as an alternative system. 15. Skewed beams shall utilize the link-beam fabrication method with CJP welded splices for skew angles. The skew angle shall be less than 15 degrees. 16. For two-sided bolted sideplate connections sharing the same side plates at the same height and depth across the column, the vertical offset in the beams shall not exceed 10 inches (254 mm).

  • CBC § 1408.10.4 High relevance — show source text

    1408.10.4 Full-scale tests. The HPL system shall be tested in accordance with, and comply with, the acceptance criteria of NFPA 285. Such testing shall be performed on the HPL system with the HPL in the minimum and maximum thicknesses intended for use.

    1408.11 Alternate conditions. HPL and HPL systems shall not be required to comply with Sections 1408.10.1 through 1408.10.4 provided that such systems comply with Section 1408.11.1.

    1408.11.1 Installations up to 40 feet in height. HPL shall be permitted to be installed up to 40 feet (12 190 mm) in height above grade plane where installed in accordance with Section 1408.11.1.1 or 1408.11.1.2.

    1408.11.1.1 Fire separation distance of 5 feet or less. Where the fire separation distance is 5 feet (1524 mm) or less, the area of HPL shall not exceed 10 percent of the exterior wall surface.

    1408.11.1.2 Fire separation distance greater than 5 feet. Where the fire separation distance is greater than 5 feet (1524 mm), the area of exterior wall surface coverage using HPL shall not be limited.

    1408.12 Type V construction. HPL shall be permitted to be installed on buildings of Type V construction.

    1408.13 Foam plastic insulation. HPL systems containing foam plastic insulation shall comply with the requirements of Section 2603.

    1408.14 Labeling. HPL shall be labeled in accordance with Section 1703.5.

    SECTION 1409—INSULATED METAL PANEL (IMP)

    1409.1 General. The provisions of this section, in addition to the other applicable requirements of this chapter and Chapter 16, shall govern the materials, construction and quality of insulated metal panels (IMP) for use as exterior walls and exterior wall coverings.

    1409.2 Structural design. Structural design of IMP systems shall be in accordance with this section.

    1409.2.1 IMP systems used as exterior walls. IMP systems used as exterior walls shall be designed and constructed to resist design loads in accordance with applicable provisions of Chapter 16.

    1409.2.2 IMP systems used as exterior wall coverings. IMP systems used as exterior wall covering systems shall be designed and constructed to resist wind loads as required by Section 1609.

    1409.2.3 Approval. Results of approved tests or engineering analyses shall be submitted to the building official to verify compliance with the applicable requirements of Chapter 16.

    1409.3 Weather resistance. IMP systems shall comply with Section 1402 and shall be designed and constructed to resist wind and rain in accordance with this section and the manufacturer’s installation instructions.

    1409.4 Durability. IMP systems shall be constructed of approved materials that maintain the performance characteristics required in Section 1402 for the duration of use.

    1409.5 Fire-resistance rating. Evidence of the required fire-resistance rating of IMP systems shall be in accordance with this section.

    2025 CALIFORNIA BUILDING CODE 14-19

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

    EXTERIOR WALLS

Frequently asked questions

If my HPL or MCM is tested to NFPA 285, do I still need to follow the 10%/40 ft rule in §1405?

Full‑scale testing such as NFPA 285 can be an alternate compliance path where §§1406/1408 permit it, but whether the 10%/40‑ft numeric limits still apply depends on the specific system section language — HPL provides an explicit alternate for up to 40 ft with area limits tied to separation; MCM has specific requirements for >40 ft (thermal barrier or testing). Always cite the specific system section and submit test reports to the building official (§1406.10.3; §1408.10.4) file.

Does EIFS always count as combustible cladding and trigger the 10% rule?

EIFS is regulated by §1407 and must meet ASTM E2568; EIFS systems are cross‑referenced to §2603 and may be restricted by the foam‑plastic rules in Chapter 26. Whether the 10% rule applies depends on the building type and the presence of combustible components; §1407.5 directs EIFS assemblies to comply with §2603. Consult §1407 and §2603 for the assembly specifics .

Where can I find the numeric separation vs. radiant-flux data used for ignition limits?

Table 1405.1.1.1.2 in §1405.1.1.1.2 provides the minimum fire separation distances and the tolerable level of incident radiant heat flux used to assess ignition / sustained flaming per NFPA 268; that table appears in §1405.1.1.1.2 in the CBC excerpts .

If my cladding is furred off the wall, do I need to fireblock the cavity?

Yes — furred‑out combustible exterior wall coverings that form a concealed space generally must keep the back gap ≤ 1 5/8" or the concealed space must be fireblocked per §718; see §1405.1.3 for the CBC rule and its exception .

Where are the detailed foam‑plastic (insulation) rules for claddings that contain foam?

Those details live in §2603 (Chapter 26). The CBC sections for MCM, EIFS and HPL explicitly cross‑reference §2603 when foam plastic insulation is present (§1406.12; §1407.5; §1408.13). The excerpts retrieved reference §2603 but did not include full §2603 clause text, so consult Chapter 26 in the CBC for exact limits, test methods and allowable configurations file.

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