CBC · California Building Code

What fire‑resistance ratings are required for structural members?

The CBC says the required fire‑resistance time for a structural member comes from the building’s type of construction (Table 601). Section 704 then requires you to protect members accordingly: primary frame members generally need individual encasement on all sides (continuous through ceilings for columns), while some primary and many secondary members can accept protection from a rated wall or ceiling membrane if that membrane provides the required rating. Check Table 601 for the actual hour requirement and then follow § 704 for how to achieve that rating.

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Last reviewed: July 5, 2026

What the code requires — 2–4 sentences

The California Building Code (CBC) requires that the fire‑resistance ratings for structural members be at least the rating required for the type of construction (Table 601) and that protection of structural members follow the prescriptions in Section 704. In plain terms: determine the rating from Table 601, then protect primary and secondary members in the manner required by Section 704 (§ 704.1).

Requirements in detail

Core rule

  • The fire‑resistance ratings of structural members and assemblies must comply with Section 704 and the type‑of‑construction requirements in Table 601 (i.e., the specific time period — 1‑, 2‑, 3‑, 4‑hour — comes from Table 601) (§ 704.1).

Protection of the primary structural frame

  • Members of the primary structural frame that are required to be protected to achieve a fire‑resistance rating must be given individual encasement protection on all sides for their full length, including connections, using materials that provide the required fire‑resistance period (§ 704.2). If a column passes through a ceiling, that encasement must be continuous from the top of the foundation or the floor/ceiling below through the ceiling space to the top of the column (§ 704.2).

  • Exceptions to the all‑sides encasement requirement (see § 704.2 exceptions):

    1. Encasing on all exposed sides is permitted provided the extent of protection meets the required rating as determined in Section 703. (§ 704.2, Exception 1).
    2. Primary structural members other than columns that do not support more than two floors (or one floor and a roof), or that do not support a load‑bearing wall or a nonload‑bearing wall more than two stories high, may be protected by the membrane of a fire‑resistance‑rated wall or horizontal assembly when that membrane provides the required rating (§ 704.2, Exception 2).
    3. Columns that meet the limitations of § 704.3.1 (light‑frame exceptions) may be treated per that section (§ 704.2, Exception 3).

Protection of secondary structural members

  • Secondary structural members required to have protection may be protected either by individual encasement or by the membrane of a fire‑resistance‑rated wall or horizontal assembly where that membrane gives the required rating (§ 704.3). Light‑frame studs/columns integral to walls and located entirely between top/bottom plates may receive the rating from the wall membrane (§ 704.3.1). Horizontal assemblies may be protected by a ceiling or membrane when installed per § 711 (§ 704.3, § 704.3.1, § 704.3.2).

Related installation/detail rules (short list)

  • Attachments (lugs, brackets, bolt heads) may extend to within 1 inch of the fire protection surface; secondary steel attachments tied to protected primary members must receive the same protection for at least 12 inches away from the member (or full length if shorter) (§ 704.5, § 704.5.1).
  • Do not embed pipes, wires, conduits, ducts, etc. in required individual encasements (§ 704.7).
  • Impact protection: where the protective covering is subject to impact, provide corner guards or a substantial noncombustible jacket not less than 5 ft high from finished floor (exception for concrete columns in parking garages) (§ 704.8).
  • Bottom flange of lintels/shelf angles: protection not required for bottom flange of lintels/shelf angles spanning 6 ft‑4 in or less, and for bottom flange of those not part of structural frame regardless of span (§ 704.10).

Decision table (quick reference)

Decision factor Required treatment Code reference
Which rating (minutes/hours) applies Determined by type of construction (Table 601). Section 704 requires compliance with that rating (§ 704.1). § 704.1
Primary structural frame (columns, primary trusses) Individual encasement protection on all sides, full length, including connections; encasement continuous through ceilings for columns extending through ceiling spaces (§ 704.2). § 704.2
Primary member—not a column & limited support (≤ 2 floors or 1 floor+roof) May be protected by membrane of a fire‑resistance‑rated wall/horizontal assembly if that membrane provides the required rating (Exception to § 704.2). § 704.2 (Exception 2)
Secondary structural members Individual encasement OR membrane protection where membrane provides the required rating (§ 704.3). § 704.3
Light‑frame studs/columns integral to wall May receive required rating from wall membrane if located entirely between top and bottom plates (§ 704.3.1). § 704.3.1
Attachments to protected members Equal protection for connected secondary steel; protection to extend ≥ 12 in or full length if shorter (§ 704.5.1). § 704.5.1
Prohibited embedding Do not embed pipes/wires/conduits in required individual encasement (§ 704.7). § 704.7

Exceptions & special cases

  • The numeric time (1, 2, 3, 4 hours) is not stated in Section 704 itself — the required time is taken from Table 601 (type of construction) or from other sections that reference ratings (for example exterior walls and separation distance). You must consult Table 601 (and Table 705.5 where exterior separation governs) to get the actual hour value for your building (§ 704.1).
  • Membrane protection (the wall or ceiling assembly itself) can be used to protect some members where the membrane provides the same rating (allowed for some primary members and for secondary members) (§ 704.2, § 704.3).
  • Light‑frame construction has relaxed rules for studs/columns that are fully within the wall framing; these can take the rating from the wall membrane (§ 704.3.1).
  • Special rules apply for mass timber, trusses and seismic isolation systems — see §§ 704.4 and 704.11 for test/assembly requirements and for ensuring isolation systems provide equivalent fire resistance to the element in which they are installed. These are treated in the same section but require referenced testing/approval methods (§ 704.4, § 704.11).

Common mistakes

  • Assuming a fixed hour (e.g., “all columns must be 2‑hour”) without checking Table 601 for the building’s type of construction and occupancy — § 704.1 requires use of Table 601 to determine the required time.
  • Protecting only visible faces of columns when the code requires continuous encasement through ceilings (columns that extend through a ceiling must be protected continuously from the foundation/floor below through the ceiling space to top of column) (§ 704.2).
  • Embedding pipes, ducts or conduits into the required encasement (this is prohibited) (§ 704.7).
  • Failing to protect secondary attachments: secondary steel directly connected to protected primary steel must receive the same protection or meet the 12‑inch rule (§ 704.5.1).
  • Confusing membrane contribution: a wall or ceiling membrane only counts if that assembly, as installed, provides the required rating (§ 704.3, § 704.2 Exception 2).

Worked example — applying the rule (step‑by‑step)

Scenario: You are designing the primary frame for a three‑story Type IIIA apartment building. You need to know how to protect the columns.

  1. Determine the numeric fire‑resistance rating for the "primary structural frame" from Table 601 for Type IIIA construction (Table 601 is outside Section 704; § 704.1 points you to Table 601 to get the required time). The CBC text in Section 704 does not itself list the minute/hour values — they come from Table 601 (§ 704.1). Check Table 601 for the actual hour requirement for primary frame in Type IIIA.

  2. Suppose (for illustration only) Table 601 requires a 2‑hour rating for the primary frame in this construction type. Under § 704.2 you must provide individual encasement protection to each primary member (columns) on all sides for the full length, including connections, with materials that achieve the 2‑hour rating. If a column passes through a ceiling, the column’s encasement must be continuous from top of foundation or the floor/ceiling below, through the ceiling space, to the top of the column (§ 704.2).

  3. Check exceptions: if some primary framing members do not support more than two floors (or one floor and a roof), you may be permitted to protect them via the membrane of a fire‑resistance‑rated wall/horizontal assembly instead of individual encasement (§ 704.2, Exception 2). Confirm whether the member in question meets those limits (§ 704.2).

  4. Verify attachments and embedments: ensure no pipes or conduits are embedded in the encasement and that any secondary steel connected to the primary frame receives equal protection (or protection extending 12 in) (§ 704.7, § 704.5.1).

Note: the numeric “2‑hour” used above is an illustrative assumption. Always read Table 601 for the authoritative time period that applies to your building; Section 704 prescribes how to provide that rating, not the numeric value itself (§ 704.1).

Related provisions

  • § 704 — Fire‑resistance rating of structural members (this section; overarching requirement).
  • § 704.1 — Requirements; ties to Table 601 (type of construction determines numeric rating).
  • § 704.2 — Protection of the primary structural frame (individual encasement, continuity through ceilings, exceptions).
  • § 704.3 / § 704.3.1 — Protection of secondary members and light‑frame exceptions (membrane allowed for studs/columns integral to wall).
  • § 704.4 — Truss protection (test/assembly basis for rated truss enclosures).
  • § 704.5 / § 704.5.1 — Attachments and secondary attachments to structural members.
  • § 704.7 — Prohibition against embedding services in required encasements.
  • § 703 — Fire‑resistance ratings and test methods (how ratings are determined/tested; referenced by § 704).
  • Table 601 — Types of construction / required ratings (used to select the numeric fire‑resistance period referenced by § 704.1).

Code references

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

  • CBC § 704.1.1 High relevance — show source text

    704.1.1 Supporting construction. The fire-resistance ratings of supporting structural members and assemblies shall be not less than the ratings required for the fire-resistance-rated assemblies supported by the structural members.

    Exception: Structural members and assemblies that support fire barriers, fire partitions, smoke barriers and horizontal assemblies as provided in Sections 707.5, 708.4, 709.4 and 711.2, respectively.

    704.2 Protection of the primary structural frame. Members of the primary structural frame that are required to have protection to achieve a fire-resistance rating shall be provided individual encasement protection by protecting them on all sides for the full length, including connections to other structural members, with materials having the required fire-resistance rating. Where a column extends through a ceiling, the encasement protection shall be continuous from the top of the foundation or floor/ceiling assembly below through the ceiling space to the top of the column.

    Exceptions:

    1. Individual encasement protection on all sides shall be permitted on all exposed sides provided that the extent of protection is in accordance with the required fire-resistance rating, as determined in Section 703.

    7-4 2025 CALIFORNIA BUILDING CODE

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

    FIRE AND SMOKE PROTECTION FEATURES

    1. Primary structural members other than columns that do not support more than two floors or one floor and roof, or a load-bearing wall or a nonload-bearing wall more than two stories high, are permitted to be protected by the membrane of a fire-resistance-rated wall or horizontal assembly where the membrane provides the required fire-resistance rating.

    2. Columns that meet the limitations of Section 704.3.1.

    704.3 Protection of secondary structural members. Secondary structural members that are required to have protection to achieve a fire-resistance rating shall be protected by individual encasement protection, or by the membrane of a fire-resistance-rated wall or horizontal assembly where the membrane provides the required fire-resistance rating.

    704.3.1 Light-frame construction. Studs, columns and boundary elements that are integral elements in walls of light-frame construction and are located entirely between the top and bottom plates or tracks shall be permitted to have required fire-resistance ratings provided by the membrane protection provided for the wall.

    704.3.2 Horizontal assemblies. Horizontal assemblies are permitted to be protected with a membrane or ceiling where the membrane or ceiling provides the required fire-resistance rating and is installed in accordance with Section 711.

    704.4 Truss protection. The required thickness and construction of fire-resistance-rated assemblies enclosing trusses shall be based on the results of full-scale tests or combinations of tests on truss components or on approved calculations based on such tests that satisfactorily demonstrate that the assembly has the required fire resistance.

    704.5 Attachments to structural members. The edges of lugs, brackets, rivets and bolt heads attached to structural members shall be permitted to extend to within 1 inch (25 mm) of the surface of the fire protection.

  • CBC § 704.5.1 High relevance — show source text

    704.5.1 Secondary attachments to structural members. Where primary and secondary structural steel members require fire protection, any additional structural steel members having direct connection to the primary structural frame or secondary structural members shall be protected with the same fire-resistive material and thickness as required for the structural member. The protection shall extend away from the structural member a distance of not less than 12 inches (305 mm), or shall be applied to the entire length where the attachment is less than 12 inches (305 mm) long. Where an attachment is hollow and the ends are open, the fire-resistive material and thickness shall be applied to both exterior and interior of the hollow steel attachment.

    704.6 Reinforcing. Thickness of protection for concrete or masonry reinforcement shall be measured to the outside of the reinforcement except that stirrups and spiral reinforcement ties are permitted to project not more than 0.5 inch (12.7 mm) into the protection.

    704.7 Embedments and enclosures. Pipes, wires, conduits, ducts or other service facilities shall not be embedded in the required fire protective covering of a structural member that is required to be individually encased.

    704.8 Impact protection. Where the fire protective covering of a structural member is subject to impact damage from moving vehicles, the handling of merchandise or other activity, the fire protective covering shall be protected by corner guards or by a substantial jacket of metal or other noncombustible material to a height adequate to provide full protection, but not less than 5 feet (1524 mm) from the finished floor.

    Exception: Corner protection is not required on concrete columns in parking garages.

    704.9 Exterior structural members. Load-bearing structural members located within the exterior walls or on the outside of a building or structure shall be provided with the highest fire-resistance rating as determined in accordance with the following:

    1. As required by Table 601 for the type of building element based on the type of construction of the building.
    2. As required by Table 601 for exterior bearing walls based on the type of construction.
    3. As required by Table 705.5 for exterior walls based on the fire separation distance.

    704.10 Bottom flange protection. Fire protection is not required at the bottom flange of lintels, shelf angles and plates, spanning not more than 6 feet 4 inches (1931 mm) whether part of the primary structural frame or not, and from the bottom flange of lintels, shelf angles and plates not part of the structural frame, regardless of span.

    704.11 Seismic isolation systems. Fire-resistance ratings for the isolation system shall meet the fire-resistance rating required for the columns, walls or other structural elements in which the isolation system is installed in accordance with Table 601. Isolation systems required to have a fire-resistance rating shall be protected with approved materials or construction assemblies designed to provide the same degree of fire resistance as the structural element in which the system is installed when tested in accordance with ASTM E119 or UL 263 (see Section 703.2).

    Such isolation system protection applied to isolator units shall be capable of retarding the transfer of heat to the isolator unit in such a manner that the required gravity load-carrying capacity of the isolator unit will not be impaired after exposure to the standard time-temperature curve fire test prescribed in ASTM E119 or UL 263 for a duration not less than that required for the fire-resistance rating of the structure element in which the system is installed.

  • CBC § 703.7 High relevance — show source text

    The test assemblies shall be identical in construction, loading and materials, other than the noncombustible protection. The two test assemblies shall be tested to the same criteria of structural failure with the following conditions:

    1. Test Assembly 1 shall be without protection.
    2. Test Assembly 2 shall include the representative noncombustible protection. The protection shall be fully defined in terms of configuration details, attachment details, joint sealing details, accessories and all other relevant details.

    The noncombustible protection time contribution shall be determined by subtracting the fire-resistance time, in minutes, of Test Assembly 1 from the fire-resistance time, in minutes, of Test Assembly 2.

    703.7 Sealing of adjacent mass timber elements. In buildings of Types IV-A, IV-B and IV-C construction, sealant or adhesive shall be provided to resist the passage of air in the following locations:

    1. At abutting edges and intersections of mass timber building elements required to be fire-resistance rated.
    2. At abutting intersections of mass timber building elements and building elements of other materials where both are required to be fire-resistance rated.

    Sealants shall meet the requirements of ASTM C920. Adhesives shall meet the requirements of ASTM D3498.

    Exception: Sealants or adhesives need not be provided where they are not a required component of a tested fire-resistance-rated assembly.

    SECTION 704—FIRE-RESISTANCE RATING OF STRUCTURAL MEMBERS

    704.1 Requirements. The fire-resistance ratings of structural members and assemblies shall comply with this section and the requirements for the type of construction as specified in Table 601.

    704.1.1 Supporting construction. The fire-resistance ratings of supporting structural members and assemblies shall be not less than the ratings required for the fire-resistance-rated assemblies supported by the structural members.

    Exception: Structural members and assemblies that support fire barriers, fire partitions, smoke barriers and horizontal assemblies as provided in Sections 707.5, 708.4, 709.4 and 711.2, respectively.

    704.2 Protection of the primary structural frame. Members of the primary structural frame that are required to have protection to achieve a fire-resistance rating shall be provided individual encasement protection by protecting them on all sides for the full length, including connections to other structural members, with materials having the required fire-resistance rating. Where a column extends through a ceiling, the encasement protection shall be continuous from the top of the foundation or floor/ceiling assembly below through the ceiling space to the top of the column.

    Exceptions:

    1. Individual encasement protection on all sides shall be permitted on all exposed sides provided that the extent of protection is in accordance with the required fire-resistance rating, as determined in Section 703.

    7-4 2025 CALIFORNIA BUILDING CODE

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

    FIRE AND SMOKE PROTECTION FEATURES

    1. Primary structural members other than columns that do not support more than two floors or one floor and roof, or a load-bearing wall or a nonload-bearing wall more than two stories high, are permitted to be protected by the membrane of a fire-resistance-rated wall or horizontal assembly where the membrane provides the required fire-resistance rating.

    2. Columns that meet the limitations of Section 704.3.1.

  • CBC § 420.2 High relevance — show source text

    Groups I-1, R-1, R-2, R-3 and R-4 420.2 Group I-3 408.7 Supporting construction 708.4.2 Fire Prevention 101.4.5

    Fire Protection

    Explosion control 414.5.1, 415.6, 421.6, 426.1.4 Fire extinguishers, portable 906 Glazing, rated 716.1.2.3 Smoke and heat removal 910 Smoke control systems 909 Sprinkler systems, automatic 903 Fire Protection Systems Chapter 9, 107.2.2 Fire Protective Curtain Assembly 716.4 Fire Pumps 403.3.2, 902.1, 913, 914.2 Fire Resistance

    Calculated 722

    Conditions of restraint 703.2.1.3 Ducts and air transfer openings 717 Exterior walls 705.5, Table 705.5,

    708.5

    Fire district D102.2.5 High-rise 403.2 Joint systems 715 Multiple use fire assemblies 702.1 Prescriptive 721 Ratings Chapter 6, 703, 705.5, 707.3.10 Roof assemblies 1505

    Structural members 704

    Tests 703 Thermal and sound insulating materials 720.1 Fire Resistance, Calculated 722 Clay brick and tile masonry 722.4 Concrete assemblies 722.2

    Concrete masonry 722.3 Steel assemblies 722.5

    Wood assemblies 722.6 Fire Separation Distance Table 705.5 Exterior walls

    1405.1.1.1.1, 1405.1.1.1.2 Ground-mounted photovoltaic systems 3111.3.6

    Fire Service Access Elevators 403.6.1, 3007 Fire Walls 706 Aircraft hangar 412.3.6.2 Combustible framing 706.7 Continuity 706.5, 706.6 Exterior walls Table 705.5, 706.5.1 Fire-resistance rating 703, 706.4 Glazing, rated 716.3.4 Inspection 110.3.8 Joints 706.10, 715 Materials 706.3

    Opening protection 706.8, 706.11, 714.4, 716, 717.5.1 Penetration 706.9, 714.4 Special provisions Covered and open mall buildings 402.4.2.2

    Group H-5 415.11.1.6 Structural stability 706.2 Fire Windows (see Opening Protectives) Fireblocking 718.2 Chimneys 718.2.5.1, 2113.20 Fireplaces 2111.13 Wood construction 718.2.1, 718.2.7,

    1405.1.3 Wood stairways 718.2.4 Fireplaces, Factory-Built 2111.14.1 Fireplaces, Masonry 202 Clearance to combustibles 2111.12

    Drawings 2111.2 General provisions 2111 Hearth extension 2111.10, 2111.11 Steel units 2111.6.1

    Fire-Resistant Construction 701.1

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

    505 Mezzanines and Equipment Platforms. . . . . . . . . . . . 5-8

    506 Building Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

    507 Unlimited Area Buildings. . . . . . . . . . . . . . . . . . . . . . . 5-13

    508 Mixed Use and Occupancy. . . . . . . . . . . . . . . . . . . . . . 5-15

    509 Incidental Uses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18

    510 Special Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

    CHAPTER 6 TYPES OF CONSTRUCTION . . . . . . . . . . . . . . . 6-1

    601 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

    602 Construction Classification. . . . . . . . . . . . . . . . . . . . . . 6-3

    603 Combustible Material in Types I and II Construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

    CHAPTER 7 FIRE AND SMOKE PROTECTION FEATURES. . 7-1

    701 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

    702 Multiple-Use Fire Assemblies . . . . . . . . . . . . . . . . . . . . 7-3

    703 Fire-Resistance Ratings and Fire Tests . . . . . . . . . . . . 7-3

    704 Fire-Resistance Rating of Structural Members . . . . . 7-4

    705 Exterior Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6

    706 Fire Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12

    707 Fire Barriers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14

    708 Fire Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16

    709 Smoke Barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17

    710 Smoke Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-18

    711 Floor and Roof Assemblies. . . . . . . . . . . . . . . . . . . . . . 7-19

  • CBC § 704.3.1. High relevance — show source text

    FIRE AND SMOKE PROTECTION FEATURES

    1. Primary structural members other than columns that do not support more than two floors or one floor and roof, or a load-bearing wall or a nonload-bearing wall more than two stories high, are permitted to be protected by the membrane of a fire-resistance-rated wall or horizontal assembly where the membrane provides the required fire-resistance rating.

    2. Columns that meet the limitations of Section 704.3.1.

    704.3 Protection of secondary structural members. Secondary structural members that are required to have protection to achieve a fire-resistance rating shall be protected by individual encasement protection, or by the membrane of a fire-resistance-rated wall or horizontal assembly where the membrane provides the required fire-resistance rating.

    704.3.1 Light-frame construction. Studs, columns and boundary elements that are integral elements in walls of light-frame construction and are located entirely between the top and bottom plates or tracks shall be permitted to have required fire-resistance ratings provided by the membrane protection provided for the wall.

    704.3.2 Horizontal assemblies. Horizontal assemblies are permitted to be protected with a membrane or ceiling where the membrane or ceiling provides the required fire-resistance rating and is installed in accordance with Section 711.

    704.4 Truss protection. The required thickness and construction of fire-resistance-rated assemblies enclosing trusses shall be based on the results of full-scale tests or combinations of tests on truss components or on approved calculations based on such tests that satisfactorily demonstrate that the assembly has the required fire resistance.

    704.5 Attachments to structural members. The edges of lugs, brackets, rivets and bolt heads attached to structural members shall be permitted to extend to within 1 inch (25 mm) of the surface of the fire protection.

    704.5.1 Secondary attachments to structural members. Where primary and secondary structural steel members require fire protection, any additional structural steel members having direct connection to the primary structural frame or secondary structural members shall be protected with the same fire-resistive material and thickness as required for the structural member. The protection shall extend away from the structural member a distance of not less than 12 inches (305 mm), or shall be applied to the entire length where the attachment is less than 12 inches (305 mm) long. Where an attachment is hollow and the ends are open, the fire-resistive material and thickness shall be applied to both exterior and interior of the hollow steel attachment.

    704.6 Reinforcing. Thickness of protection for concrete or masonry reinforcement shall be measured to the outside of the reinforcement except that stirrups and spiral reinforcement ties are permitted to project not more than 0.5 inch (12.7 mm) into the protection.

    704.7 Embedments and enclosures. Pipes, wires, conduits, ducts or other service facilities shall not be embedded in the required fire protective covering of a structural member that is required to be individually encased.

    704.8 Impact protection. Where the fire protective covering of a structural member is subject to impact damage from moving vehicles, the handling of merchandise or other activity, the fire protective covering shall be protected by corner guards or by a substantial jacket of metal or other noncombustible material to a height adequate to provide full protection, but not less than 5 feet (1524 mm) from the finished floor.

    Exception: Corner protection is not required on concrete columns in parking garages.

  • CBC § 7-3 High relevance — show source text

    702 Multiple-Use Fire Assemblies . . . . . . . . . . . . . . . . . . . . 7-3

    703 Fire-Resistance Ratings and Fire Tests . . . . . . . . . . . . 7-3

    704 Fire-Resistance Rating of Structural Members . . . . . 7-4

    705 Exterior Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6

    706 Fire Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12

    707 Fire Barriers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14

    708 Fire Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16

    709 Smoke Barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17

    710 Smoke Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-18

    711 Floor and Roof Assemblies. . . . . . . . . . . . . . . . . . . . . . 7-19

    712 Vertical Openings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20

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

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

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

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

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

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

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

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

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

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

    CHAPTER 7A [SFM] MATERIALS AND CONSTRUCTION

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

  • CBC § 2.1 High relevance — show source text

    2.1_||||X|X||||||||||||||||||||

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

    2025 CALIFORNIA BUILDING CODE 7-1

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

    7-2 2025 CALIFORNIA BUILDING CODE

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

    7 FIRE AND SMOKE PROTECTION FEATURES

    User notes:

    About this chapter: Chapter 7 provides detailed requirements for fire-resistance-rated construction, including structural members, walls, partitions and horizontal assemblies. Other portions of the code describe where certain fire-resistance-rated elements are required. This chapter specifies how these elements are constructed, how openings in walls and partitions are protected and how penetrations of such elements are protected.

    SECTION 701—GENERAL

    701.1 Scope. The provisions of this chapter shall govern the materials, systems and assemblies used for structural fire resistance and fire-resistance-rated construction separation of adjacent spaces to safeguard against the spread of fire and smoke within a building and the spread of fire to or from buildings.

    SECTION 702—MULTIPLE-USE FIRE ASSEMBLIES

    702.1 Multiple-use fire assemblies. Fire assemblies that serve multiple purposes in a building shall comply with all of the requirements that are applicable for each of the individual fire assemblies.

    SECTION 703—FIRE-RESISTANCE RATINGS AND FIRE TESTS

    703.1 Scope. Materials prescribed herein for fire resistance shall conform to the requirements of this chapter.

    703.2 Fire resistance. The fire-resistance rating of building elements, components or assemblies shall be determined in accordance with Section 703.2.1 or 703.2.2 without the use of automatic sprinklers or any other fire suppression system being incorporated, or in accordance with Section 703.2.3.

    703.2.1 Tested assemblies. A fire-resistance rating of building elements, components or assemblies shall be determined by the test procedures set forth in ASTM E119 or UL 263. The fire-resistance rating of penetrations and fire-resistant joint systems shall be determined in accordance with Sections 714 and 715, respectively.

    703.2.1.1 Nonsymmetrical wall construction. Interior walls and partitions of nonsymmetrical construction shall be tested with both faces exposed to the furnace, and the assigned fire-resistance rating shall be the shortest duration obtained from the two tests conducted in compliance with ASTM E119 or UL 263. Where evidence is furnished to show that the wall was tested with the least fire-resistant side exposed to the furnace, subject to acceptance of the building official, the wall need not be subjected to tests from the opposite side (see Section 705.5 for exterior walls).

    703.2.1.2 Combustible components. Combustible aggregates are permitted in gypsum and Portland cement concrete mixtures for fire-resistance-rated construction. Any component material or admixture is permitted in assemblies if the resulting tested assembly meets the fire-resistance test requirements of this code.

  • CBC § 2.1 High relevance — show source text

    Fire-retardant-treated wood members shall be
    allowed to be used for such unprotected members.
    2. For Group A, E, I, L, R-1, R-2 and R-2.1 occupancies, high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, fire protec-
    tion of members other than the primary structural frame shall not be required, including protection of roof framing and decking where every part of the roof construction is 20
    feet or more above any floor immediately below. Fire-retardant-treated wood members shall be allowed to be used for such unprotected members.
    3. One-story portions of Group A and E assembly occupancies the roof-framing system of Type II A or Type III A construction may be of unprotected construction when such roof-
    framing system is open to the assembly area and does not contain concealed spaces.
    c. In all occupancies, heavy timber complying with Section 2304.11 shall be allowed for roof construction, including primary structural frame members, where a 1-hour or less
    fire-resistance rating is required.
    d. Not less than the fire-resistance rating required by other sections of this code.
    e. Not less than the fire-resistance rating based on fire separation distance (see Table 705.5).
    f. Not less than the fire-resistance rating as referenced in Section 704.9.
    g. Heavy timber bearing walls supporting more than two floors or more than a floor and a roof shall have a fire-resistance rating of not less than 1 hour.|For SI: 1 foot = 304.8 mm.
    a. Roof supports: Fire-resistance ratings of primary structural frame and bearing walls are permitted to be reduced by 1 hour where supporting a roof only.
    b._ 1._ Except in Group_A, E,_ F-1, H,I, L,M, R-1, R-2, R-2.1 and S-1 occupancies,high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire
    _Marshal, _fire protection of structural members in roof construction shall not be required, including protection of primary structural frame members, roof framing and
    decking where every part of the roof construction is 20 feet or more above any floor or mezzanine immediately below. Fire-retardant-treated wood members shall be
    allowed to be used for such unprotected members.
    2. For Group A, E, I, L, R-1, R-2 and R-2.1 occupancies, high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, fire protec-
    tion of members other than the primary structural frame shall not be required, including protection of roof framing and decking where every part of the roof construction is 20
    feet or more above any floor immediately below. Fire-retardant-treated wood members shall be allowed to be used for such unprotected members.
    3. One-story portions of Group A and E assembly occupancies the roof-framing system of Type II A or Type III A construction may be of unprotected construction when such roof-
    framing system is open to the assembly area and does not contain concealed spaces.
    c. In all occupancies, heavy timber complying with Section 2304.11 shall be allowed for roof construction, including primary structural frame members, where a 1-hour or less
    fire-resistance rating is required.
    d.

  • CBC § 418.4 High relevance — show source text

    Organic coating 418.4, 418.5, 418.6 Stages and platforms 410.5.1, 410.5.2

    Fire Command Center 403.4.6, 412.2.3.2, 911, 3007.7, 3008.6.6, 3008.7 Fire Dampers 717.2, 717.3, 717.4, 717.5 Fire Department (see Emergency Responders) Fire Detection System (see Fire Alarm and Smoke Detection Systems) Fire District Appendix D Fire Door (see Opening Protectives) 716, 1023.4 Fire Escape 412.7.3 Fire Extinguishers, Portable 906, 3309 Fire Extinguishing Systems 416.5, 417.4, 903, 904 Fire Partition 708

    Continuity 708.4 Elevator door protection 3006 Exterior walls Table 705.5, 708.5

    Fireblocks and draftstops 708.4.3 Fire-resistance rating 603.1, 703, 708.3 Glazing, rated 716.3.4 Inspection 110.3.8 Joint treatment gypsum 2508.5 Joints 708.8, 715 Marking 703.5 Materials 708.2

    Opening protection 708.5, 714.4, 716, 717.5.4

    Penetrations 708.7, 708.9, 714, 717 Special provisions Covered and open mall buildings 402.4.2.1

    Groups I-1, R-1, R-2, R-3 and R-4 420.2 Group I-3 408.7 Supporting construction 708.4.2 Fire Prevention 101.4.5

    Fire Protection

    Explosion control 414.5.1, 415.6, 421.6, 426.1.4 Fire extinguishers, portable 906 Glazing, rated 716.1.2.3 Smoke and heat removal 910 Smoke control systems 909 Sprinkler systems, automatic 903 Fire Protection Systems Chapter 9, 107.2.2 Fire Protective Curtain Assembly 716.4 Fire Pumps 403.3.2, 902.1, 913, 914.2 Fire Resistance

    Calculated 722

    Conditions of restraint 703.2.1.3 Ducts and air transfer openings 717 Exterior walls 705.5, Table 705.5,

    708.5

    Fire district D102.2.5 High-rise 403.2 Joint systems 715 Multiple use fire assemblies 702.1 Prescriptive 721 Ratings Chapter 6, 703, 705.5, 707.3.10 Roof assemblies 1505

    Structural members 704

    Tests 703 Thermal and sound insulating materials 720.1 Fire Resistance, Calculated 722 Clay brick and tile masonry 722.4 Concrete assemblies 722.2

    Concrete masonry 722.3 Steel assemblies 722.5

    Wood assemblies 722.6 Fire Separation Distance Table 705.5 Exterior walls

  • CBC § 1023.7 High relevance — show source text

    In each case, openings into the fire-resistance-rated construction shall be limited to those needed for maintenance and operation and shall be protected by opening protectives in accordance with Section 716 of the California Building Code for shaft enclosures.

    The interior exit stairway and ramp ventilation systems shall be independent of other building ventilation systems.

    [BE] 1023.7 Interior exit stairway and ramp exterior walls. Exterior walls of the interior exit stairway or ramp shall comply with the requirements of Section 705 of the California Building Code for exterior walls. Where nonrated walls or unprotected openings enclose the exterior of the stairway or ramps and the walls or openings are exposed by other parts of the building at an angle of less than 180 degrees (3.14 rad), building construction within 10 feet (3048 mm) of the exterior walls of the interior exit stairway or ramp shall comply with Sections 1023.7.1 and 1023.7.2.

    2025 CALIFORNIA FIRE CODE 10-47

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

    MEANS OF EGRESS

    [BE] 1023.7.1 Building exterior walls. Building exterior walls within 10 feet (3048 mm) horizontally of a nonrated wall or unprotected opening in an interior exit stairway or ramp shall have a fire-resistance rating of not less than 1 hour. Openings within such exterior walls shall be protected by opening protectives having a fire protection rating of not less than [3] / 4 hour. This construction shall extend vertically from the ground to a point 10 feet (3048 mm) above the topmost landing of the stairway or ramp, or to the roof line, whichever is lower.

    [BE] 1023.7.2 Roof assemblies. Where the interior exit stairway or ramp extends above an adjacent roof of the same building, the adjacent roof assembly shall have a fire-resistance rating of not less than 1 hour and openings shall be protected by opening protectives having a fire protection rating of not less than [3] / 4 hour. The fire-resistance rating and opening protection shall extend horizontally not less than 10 feet (3048 mm) from the exterior wall of the stairway or ramp, or to the perimeter of the adjacent roof, whichever is less.

    Exceptions:

    1. The roof assembly need not be rated and openings in the roof need not be protected where they are adjacent to the penthouse of the stairway or ramp, unless otherwise required by this code.
    2. The adjacent roof assembly need not be rated and adjacent openings in the roof need not be protected where the exterior wall of the stairway or ramp has a fire-resistance rating of 1 hour and openings are protected by opening protectives having a fire protection rating of not less than [3] / 4 hour, extending not less than 10 feet (3048 mm) above the roof.

    [BE] 1023.8 Barriers at level of exit discharge. An interior exit stairway and ramp shall not continue below its level of exit discharge unless an approved barrier is provided at the level of exit discharge to prevent persons from unintentionally continuing into levels below. Directional exit signs shall be provided as specified in Section 1013.

  • CBC § 25.4 High relevance — show source text

    This table applies only to wood joist construction. It is not applicable to wood truss construction.|For SI: 1 inch = 25.4 mm.
    a. This table applies only to wood joist construction. It is not applicable to wood truss construction.|For SI: 1 inch = 25.4 mm.
    a. This table applies only to wood joist construction. It is not applicable to wood truss construction.|

    TABLE 722.6.2(5)—TIME ASSIGNED FOR ADDITIONAL PROTECTION Col2
    DESCRIPTION OF ADDITIONAL PROTECTION FIRE RESISTANCE
    (minutes)
    Add to the fire-resistance rating of wood stud walls if the spaces between the studs are completely filled with glass
    fiber mineral wool batts weighing not less than 2 pounds per cubic foot (0.6 pound per square foot of wall surface),
    or cellulose insulation having a nominal density not less than 2.6 pounds per cubic foot.    		 15
    For SI: 1 pound/cubic foot = 16.0185 kg/m3. For SI: 1 pound/cubic foot = 16.0185 kg/m3.

    722.6.2.1 Fire-resistance rating of wood frame assemblies. The fire-resistance rating of a wood frame assembly is equal to the sum of the time assigned to the membrane on the fire-exposed side, the time assigned to the framing members and the time assigned for additional contribution by other protective measures such as insulation. The membrane on the unexposed side shall not be included in determining the fire resistance of the assembly.

    722.6.2.2 Time assigned to membranes. Table 722.6.2(1) indicates the time assigned to membranes on the fire-exposed side.

    722.6.2.3 Exterior walls. For an exterior wall with a fire separation distance greater than 10 feet (3048 mm), the wall is assigned a rating dependent on the interior membrane and the framing as described in Table 722.6.2(1) and Table 722.6.2(2). The membrane on the outside of the nonfire-exposed side of exterior walls with a fire separation distance greater than 10 feet (3048 mm) shall consist of sheathing, sheathing paper and siding as described in Table 722.6.2(3).

    722.6.2.4 Floors and roofs. In the case of a floor or roof, the standard test provides only for testing for fire exposure from below. Except as noted in Section 703.2.3, floor or roof assemblies of wood framing shall have an upper membrane consisting of a subfloor and finished floor conforming to Table 722.6.2(4) or any other membrane that has a contribution to fire resistance of not less than 15 minutes in Table 722.6.2(1).

    722.6.2.5 Additional protection. Table 722.6.2(5) indicates the time increments to be added to the fire resistance where glass fiber, rockwool, slag mineral wool or cellulose insulation is incorporated in the assembly.

    722.6.2.6 Fastening. Fastening of wood frame assemblies and the fastening of membranes to the wood framing members shall be done in accordance with Chapter 23.

    722.7 Fire-resistance rating for mass timber. The required fire resistance of mass timber elements in Section 602.4 shall be determined in accordance with Section 703.2 or Section 703.3 . The fire-resistance rating of building elements shall be as required in Tables

Frequently asked questions

Who decides the number of hours (1/2/3/4) for a structural member?

The numeric fire‑resistance period is determined by the building’s type of construction and applicable tables (Table 601 and other code tables); Section 704 tells you how to provide the required protection once the time is known (§ 704.1).

Can I protect steel columns by only wrapping the exposed faces if they are inside a room?

Not unless that meets the exceptions. § 704.2 requires individual encasement protection on all sides for the full length (including connections); an exception allows exposed‑sides protection only where the extent of protection still meets the required rating or under other specifically listed exceptions (§ 704.2).

Can the wall or ceiling membrane be used instead of encasement?

Yes — secondary members and some primary members (subject to the limits in § 704.2 and § 704.3) may be protected by the membrane of a fire‑resistance‑rated wall or horizontal assembly if that membrane provides the required rating (§ 704.2, § 704.3).

Are services (pipes, ducts, wiring) allowed inside encasement material?

No. Pipes, wires, conduits, ducts or other service facilities shall not be embedded in required individual encasements (§ 704.7).

What if my attachment is hollow steel connected to a protected member?

If the attachment is hollow and open at the ends, the same fire‑resistive material and thickness must be applied to both the exterior and interior of the hollow attachment (§ 704.5.1).

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Related in the CBC

How are fire‑resistance ratings determined and tested?

Prescriptive vs calculated fire‑resistance methods (Tables and Section 721/722)

Exterior wall fire‑resistance, openings and fire‑separation distance (Table 705.5)

Fire-Resistance‑Rated Construction & Ratings

California Building Code