CFC · California Fire Code

How must joints, perimeter gaps and voids be protected in fire/smoke barriers?

Q: Do I need to upgrade joints in an old building that were not required when built?

No — unprotected joints and voids that were not required to be protected when the building was originally constructed need not be retrofitted ; however any protection that was required originally must be maintained. § 704.1 .

Q: If a joint system is damaged, what must be done?

Materials/systems used to protect joints and voids must be replaced or restored with materials or systems that meet or exceed the code requirements that applied when the assembly was constructed, remodeled or altered. § 704.2 .

Q: Are there width‑based exceptions for control joints?

Yes — control joints that do not exceed 0.625 inch (15.9 mm) and have been tested appropriately are an exception to the fire‑resistant joint system requirement. See the exception list in § 715.3 .

Summary: Joints and gaps in fire‑ and smoke‑resistive walls, floors and curtain‑wall intersections must be protected with listed or approved systems, installed per listing/manufacturer instructions, maintained by the owner, and—where applicable for smoke barriers—meet strict air‑leakage limits (e.g., L ≤ 5 cfm/ft at 0.30 in. w.g.).

Ask a question free See coverage

Last reviewed: July 6, 2026

What the code requires — 2–4 sentences

Joints, perimeter gaps and voids that affect the continuity of fire-resistance-rated and smoke‑resistive assemblies must be protected with approved systems or materials and maintained for the life of the building. The owner must keep the protection intact, and repairs must restore at least the level of protection originally required. See § 704.1 and § 704.2 for maintenance/repair obligations and § 715.1–§ 715.3 for the types of protection and installation requirements.

The single most important rule: keep the listed/approved joint, perimeter containment and smoke‑control materials installed and intact — and restore them to at least their original tested/listed performance if damaged.

Requirements in detail

What locations are covered (where protection must be maintained)

Joints in or between fire‑resistance‑rated walls, floors, roofs. § 704.1.
Joints in smoke barriers. § 704.1.
Voids at intersections (floor vs exterior curtain wall, smoke barrier vs curtain wall, vertical fire barrier vs curtain wall or non‑rated roof, etc.). § 704.1.

What products/systems must be used and how they must be installed

Use a listed fire‑resistant joint system, perimeter fire containment system, or continuity head‑of‑wall system where required; install per the listing and manufacturer instructions for the full length so they can accommodate expected building movement and resist fire/smoke passage. § 715.2.1, § 715.2.2.
Joints between fire‑resistance‑rated assemblies must be protected by an approved fire‑resistant joint system whose fire‑resistance time is not less than the rating of the adjacent assembly. § 715.3.

Required test standards (where CFC specifies)

Fire‑resistant joint systems used in rated assemblies are required to be tested to the applicable standard(s) specified in §715 (see the code for the test standards referenced). § 715.3.1.
Perimeter fire containment systems at curtain wall / floor intersections must provide an F rating at least equal to the required fire‑resistance rating of the floor assembly and be tested to the standard identified in the code. § 715.4, § 715.4.1.

Smoke‑barrier specific limits

Joint systems protecting smoke barriers — and perimeter fire containment systems at the intersection of a horizontal smoke barrier and an exterior curtain wall — must be tested for air leakage in accordance with the referenced test protocol (UL 2079 as specified) and meet the leakage limit below. § 715.9.

Decision‑relevant dimensions/values

Item	Decision‑relevant value	Code Reference
Maximum L‑rating (air leakage) for joints in smoke barriers	5 cubic feet per minute per linear foot (0.00775 m3/s·m) of joint at 0.30 inch of water (74.7 Pa) (ambient & elevated)	§ 715.9
Perimeter system fire rating requirement	Must provide an F rating not less than the fire‑resistance rating of the floor/floor‑ceiling assembly	§ 715.4
Control joint exception width	0.625 inch (15.9 mm) (control joints ≤ this width are an exception)	§ 715.3 (exceptions)
Maintenance / repair requirement	Materials/systems used originally must be maintained; where damaged they must be replaced or restored to meet or exceed the original code requirement	§ 704.1, § 704.2

Exceptions & special cases

Unprotected joints/voids that were not required to be protected at the time the building was originally constructed need not be retrofitted. § 704.1.
Several location‑specific exceptions apply to fire‑resistant joint systems (e.g., certain floors within single dwelling units, shafts, atriums, some parking garages, mezzanines, walls permitted to have unprotected openings, certain control joints). See the exception list under § 715.3 for the complete set. § 715.3 (exceptions).
For smoke barriers, the code imposes an air‑leakage performance limit (the L rating) tested per the referenced test protocol; systems must meet the leakage limit for both ambient and elevated temperature tests. § 715.9.

If a specific test standard or a narrow exception you expect is not discussed above, that detail either appears elsewhere in the code or is not present in the CFC text retrieved for §§704/715 — check the referenced subsection in the code or consult the listing/manufacturer documentation and the authority having jurisdiction.

Common mistakes

Relying on unlisted “patch” materials or loose fill rather than a listed system or approved material installed per the manufacturer — installation must follow listing/manufacturer instructions. § 715.2.1, § 715.2.2.
Forgetting to maintain protection that was required at original construction (owner responsibility). § 704.1, § 704.2.
Treating smoke‑barrier joints like ordinary joints — smoke barriers demand tested air‑leakage performance (L rating) and have tight leakage limits. § 715.9.
Installing a joint system whose fire rating is lower than the adjacent assembly — the joint system’s assigned rating must be not less than the adjacent assembly’s rating. § 715.3.

Worked example — concrete scenario with numbers

Scenario: a horizontal smoke barrier runs along a 30‑ft length where it meets a glazed exterior curtain wall. You specify a listed joint system to protect the head‑of‑wall joint.

Code requirement: The joint system must be tested to the air‑leakage test protocol referenced by the code (UL 2079) and its L rating must not exceed 5 cfm per linear foot at 0.30 in. w.g. (74.7 Pa) in both ambient and elevated tests. § 715.9.
Allowed leakage for this 30‑ft joint = 5 cfm/ft × 30 ft = 150 cfm at 0.30 in. w.g. (both ambient and elevated). § 715.9.
Installation: install the listed system per the manufacturer/listing for the entire 30‑ft length so it accommodates movement and remains securely attached. § 715.2.1.
Maintenance: the owner must maintain the system and, if damaged, restore the protection per § 704.2.

If instead the joint were between two fire‑resistance‑rated floor assemblies, the joint system would be required to provide a fire‑resistance duration not less than the rating of the floor assembly (install a listed fire‑resistant joint system with the matching F/through rating). § 715.3.

Related provisions

Owner maintenance and inspection duties — § 701.6 (owner responsibility)
Penetrations (penetration firestops) — § 703.1–703.2 (maintain and repair penetrations)
Penetrations in smoke barriers (air‑leakage limits for through‑penetration firestop systems) — § 714.5.4 (L‑rating criteria for through‑penetrations)
Smoke barrier construction and allowable leakage ratios for passive smoke control — § 909.5 (interaction with smoke control systems; leakage area concepts)

Code references

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

CFC § 0.01 High relevance — show source text
Exception: Voids created at the intersection of the exterior curtain wall assemblies and floor assemblies where the vision glass extends to the finished floor level shall be permitted to be protected with an approved material to prevent the interior spread of fire. Such material shall be securely installed and capable of preventing the passage of flame and hot gases sufficient to ignite cotton waste where subjected to ASTM E119 time-temperature fire conditions under a minimum positive pressure differential of 0.01 inch of water (2.49 Pa) for the time period not less than the fire-resistance rating of the floor assembly.

715.5 Exterior curtain wall/nonfire-resistance-rated floor assembly intersections. Voids created at the intersection of exterior curtain wall assemblies and nonfire-resistance-rated floor or floor/ceiling assemblies shall be filled with an approved material or system to retard the interior spread of fire and hot gases.

Exceptions: An approved material or system to retard the interior spread of fire and hot gases shall not be required for voids in the following locations:
1. Floors within a single dwelling unit.
2. Floors and ramps within parking garages or structures constructed in accordance with Sections 406.5 and 406.6.
3. Mezzanine floors.
715.6 Fire barrier/nonfire-resistance-rated roof assembly intersections. Voids created at the intersection of a fire barrier and the underside of a nonfire-resistance-rated roof sheathing, slab or deck above shall be filled by an approved material or system to retard the passage of fire and hot gases, or shall be protected by an approved continuity head-of-wall system tested in accordance with ASTM E2837 to provide an F rating/T rating for a time period not less than the required fire-resistance rating of the fire barrier in which it is installed.

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

gases.

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

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

tests.

SECTION 716—OPENING PROTECTIVES

716.1 General. Opening protectives required by other sections of this code shall comply with the provisions of this section and shall be installed in accordance with NFPA 80.
CFC § 715.3.1 High relevance — show source text
715.3.1 Fire test criteria. Fire-resistant joint systems shall be tested in accordance with the requirements of either ASTM E1966 or UL 2079. Nonsymmetrical wall joint systems 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. 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.

Exception: For exterior walls with a horizontal fire separation distance greater than 10 feet (3048 mm), the joint system shall be required to be tested for interior fire exposure only.

715.4 Exterior curtain wall/fire-resistance-rated floor intersections. Voids created at the intersection of exterior curtain wall assemblies and fire-resistance-rated floor or floor/ceiling assemblies shall be protected with an approved perimeter fire contain

7-26 2025 CALIFORNIA BUILDING CODE

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

FIRE AND SMOKE PROTECTION FEATURES

ment system to prevent the interior spread of fire. Such systems shall provide an F rating for a time period not less than the fireresistance rating of the floor or floor/ceiling assembly.

Exceptions: An approved perimeter fire containment system shall not be required for voids in the following locations:
1. Floors within a single dwelling unit.
2. Floors and ramps within parking garages or structures constructed in accordance with Sections 406.5 and 406.6.
3. Mezzanine floors.
715.4.1 Fire test criteria. Perimeter fire containment systems shall be tested in accordance with the requirements of ASTM E2307.

Exception: Voids created at the intersection of the exterior curtain wall assemblies and floor assemblies where the vision glass extends to the finished floor level shall be permitted to be protected with an approved material to prevent the interior spread of fire. Such material shall be securely installed and capable of preventing the passage of flame and hot gases sufficient to ignite cotton waste where subjected to ASTM E119 time-temperature fire conditions under a minimum positive pressure differential of 0.01 inch of water (2.49 Pa) for the time period not less than the fire-resistance rating of the floor assembly.

715.5 Exterior curtain wall/nonfire-resistance-rated floor assembly intersections. Voids created at the intersection of exterior curtain wall assemblies and nonfire-resistance-rated floor or floor/ceiling assemblies shall be filled with an approved material or system to retard the interior spread of fire and hot gases.

Exceptions: An approved material or system to retard the interior spread of fire and hot gases shall not be required for voids in the following locations:
1. Floors within a single dwelling unit.
2. Floors and ramps within parking garages or structures constructed in accordance with Sections 406.5 and 406.6.
3. Mezzanine floors.
715.6 Fire barrier/nonfire-resistance-rated roof assembly intersections. Voids created at the intersection of a fire barrier and the underside of a nonfire-resistance-rated roof sheathing, slab or deck above shall be filled by an approved material or system to retard the passage of fire and hot gases, or shall be protected by an approved continuity head-of-wall system tested in accordance with ASTM E2837 to provide an F rating/T rating for a time period not less than the required fire-resistance rating of the fire barrier in which it is installed.
CFC § 703.2 High relevance — show source text
703.2 Repair of penetrations. Where damaged, materials used to protect membrane- and through-penetrations shall be replaced or restored with materials or systems that meet or exceed the code requirements applicable at the time when the assembly was constructed, remodeled or altered.

SECTION 704—JOINTS AND VOIDS

704.1 Maintaining protection. Where required when the building was originally constructed, materials and systems used to protect joints and voids in the following locations shall be maintained. The materials and systems shall be securely attached to or bonded to the adjacent construction, without openings visible through the construction.
1. Joints in or between fire-resistance-rated walls, floors or floor/ceiling assemblies and roof or roof/ceiling assemblies.
2. Joints in smoke barriers.
3. Voids at the intersection of a horizontal floor assembly and an exterior curtain wall.
4. Voids at the intersection of a horizontal smoke barrier and an exterior curtain wall.
5. Voids at the intersection of a nonfire-resistance-rated floor assembly and an exterior curtain wall.
6. Voids at the intersection of a vertical fire barrier and an exterior curtain wall.
7. Voids at the intersection of a vertical fire barrier and a nonfire-resistance-rated roof assembly.
Unprotected joints and voids do not need to be protected where such joints and voids were not required to be protected when the building was originally constructed. Where the system design number is known, the system shall be inspected to the listing criteria and manufacturer’s installation instructions.

704.2 Repair of joints and voids. Where damaged, materials used to protect joints and voids shall be replaced or restored with materials or systems that meet or exceed the code requirements applicable at the time when the assembly was constructed, remodeled or altered.

704.3 Opening protectives. Where openings are required to be protected, opening protectives shall be maintained self-closing or automatic-closing by smoke detection. Existing fusible-link-type automatic door-closing devices are permitted if the fusible link rating does not exceed 135°F (57°C).

SECTION 705—DOOR AND WINDOW OPENINGS

705.1 General. Where required when the building was originally constructed, opening protectives installed in fire-resistance-rated assemblies, smoke barriers and smoke partitions shall be inspected and maintained in accordance with this section.

705.2 Inspection and maintenance. Opening protectives in fire-resistance-rated assemblies shall be inspected and maintained in accordance with NFPA 80. Opening protectives in smoke barriers shall be inspected and maintained in accordance with NFPA 80 and NFPA 105. Openings in smoke partitions shall be inspected and maintained in accordance with NFPA 105. Fire doors and smoke and draft control doors shall not be blocked, obstructed, or otherwise made inoperable. Fusible links shall be replaced promptly whenever fused or damaged. Opening protectives and smoke and draft control doors shall not be modified.

705.2.1 Labeling requirements. Where approved by the fire code official, the application of field-applied labels associated with the maintenance of opening protectives shall follow the requirements of the approved third-party certification organization accredited for listing the opening protective.

705.2.2 Signs. Where required by the fire code official, a sign shall be permanently displayed on or near each fire door in letters not less than 1 inch (25 mm) high to read as follows:
1. For doors designed to be kept normally open: “FIRE DOOR—DO NOT BLOCK.”
2. For doors designed to be kept normally closed: “FIRE DOOR—KEEP CLOSED.”
CFC § 715.2.2 High relevance — show source text
715.2.2 Approved materials installation. Approved materials protecting voids shall be securely installed in accordance with the manufacturer’s installation instructions in or on the void for its entire length so as not to dislodge, loosen or otherwise impair its ability to accommodate expected building movements and to resist the passage of fire and hot gases.

715.3 Fire-resistance-rated assembly intersections. Joints installed in or between fire-resistance-rated walls, floor or floor/ceiling assemblies and roofs or roof/ceiling assemblies shall be protected by an approved fire-resistant joint system designed to resist the passage of fire for a time period not less than the required fire-resistance rating of the wall, floor or roof in or between which the system is installed.

Exception: Fire-resistant joint systems shall not be required for joints in the following locations:
1. Floors within a single dwelling unit.
2. Floors where the joint is protected by a shaft enclosure in accordance with Section 713.
3. Floors within atriums where the space adjacent to the atrium is included in the volume of the atrium for smoke control
purposes.
1. Floors within malls.
2. Floors and ramps within parking garages or structures constructed in accordance with Sections 406.5 and 406.6.
3. Mezzanine floors.
4. Walls that are permitted to have unprotected openings.
5. Roofs where openings are permitted.
6. Control joints not exceeding a maximum width of 0.625 inch (15.9 mm) and tested in accordance with ASTM E119 or UL 263.
7. The intersection of exterior curtain wall assemblies and the roof slab or roof deck.
715.3.1 Fire test criteria. Fire-resistant joint systems shall be tested in accordance with the requirements of either ASTM E1966 or UL 2079. Nonsymmetrical wall joint systems 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. 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.

Exception: For exterior walls with a horizontal fire separation distance greater than 10 feet (3048 mm), the joint system shall be required to be tested for interior fire exposure only.

715.4 Exterior curtain wall/fire-resistance-rated floor intersections. Voids created at the intersection of exterior curtain wall assemblies and fire-resistance-rated floor or floor/ceiling assemblies shall be protected with an approved perimeter fire contain

7-26 2025 CALIFORNIA BUILDING CODE

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

FIRE AND SMOKE PROTECTION FEATURES

ment system to prevent the interior spread of fire. Such systems shall provide an F rating for a time period not less than the fireresistance rating of the floor or floor/ceiling assembly.

Exceptions: An approved perimeter fire containment system shall not be required for voids in the following locations:
1. Floors within a single dwelling unit.
2. Floors and ramps within parking garages or structures constructed in accordance with Sections 406.5 and 406.6.
3. Mezzanine floors.
715.4.1 Fire test criteria. Perimeter fire containment systems shall be tested in accordance with the requirements of ASTM E2307.

CFC § 715.7 High relevance — show source text

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

gases.

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

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

tests.

SECTION 716—OPENING PROTECTIVES

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

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

2025 CALIFORNIA BUILDING CODE 7-27

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

FIRE AND SMOKE PROTECTION FEATURES

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

CFC § 714.6 High relevance — show source text
714.6 Nonfire-resistance-rated assemblies. Penetrations of nonfire-resistance-rated floor or floor/ceiling assemblies or the ceiling membrane of a nonfire-resistance-rated roof/ceiling assembly shall meet the requirements of Section 713 or shall comply with Section 714.6.1 or 714.6.2.

714.6.1 Noncombustible penetrating items. Noncombustible penetrating items that connect not more than five stories are permitted, provided that the annular space is filled to resist the free passage of flame and the products of combustion with an approved noncombustible material or with a fill, void or cavity material that is tested and classified for use in through-penetration firestop systems.

714.6.2 Penetrating items. Penetrating items that connect not more than two stories are permitted, provided that the annular space is filled with an approved material to resist the free passage of flame and the products of combustion.

SECTION 715—JOINTS AND VOIDS

715.1 General. The provisions of this section shall govern the materials and methods of construction used to protect joints and voids in or between horizontal and vertical assemblies.

715.2 Installation. Systems or materials protecting joints and voids shall be installed in accordance with Sections 715.2.1 and 715.2.2.

715.2.1 List system installation. Listed fire-resistant joint systems, perimeter fire containment systems and continuity head-ofwall systems shall be securely installed in accordance with the manufacturer’s installation instructions and the listing criteria in or on the joint or void for its entire length so as not to dislodge, loosen or otherwise impair its ability to accommodate expected building movements and to resist the passage of fire and hot gases.

715.2.2 Approved materials installation. Approved materials protecting voids shall be securely installed in accordance with the manufacturer’s installation instructions in or on the void for its entire length so as not to dislodge, loosen or otherwise impair its ability to accommodate expected building movements and to resist the passage of fire and hot gases.

715.3 Fire-resistance-rated assembly intersections. Joints installed in or between fire-resistance-rated walls, floor or floor/ceiling assemblies and roofs or roof/ceiling assemblies shall be protected by an approved fire-resistant joint system designed to resist the passage of fire for a time period not less than the required fire-resistance rating of the wall, floor or roof in or between which the system is installed.

Exception: Fire-resistant joint systems shall not be required for joints in the following locations:
1. Floors within a single dwelling unit.
2. Floors where the joint is protected by a shaft enclosure in accordance with Section 713.
3. Floors within atriums where the space adjacent to the atrium is included in the volume of the atrium for smoke control
purposes.
1. Floors within malls.
2. Floors and ramps within parking garages or structures constructed in accordance with Sections 406.5 and 406.6.
3. Mezzanine floors.
4. Walls that are permitted to have unprotected openings.
5. Roofs where openings are permitted.
6. Control joints not exceeding a maximum width of 0.625 inch (15.9 mm) and tested in accordance with ASTM E119 or UL 263.
7. The intersection of exterior curtain wall assemblies and the roof slab or roof deck.
CFC § 701.6.1 High relevance — show source text
701.6.1 Recordkeeping. Records of all required system inspections, testing, repairs and maintenance shall be maintained in accordance with Section 110.3.

701.7 Unsafe conditions. Where any components in this chapter are not maintained and do not function as intended or do not have the fire resistance or the resistance to the passage of smoke required by the code under which the building was constructed, remodeled or altered, such component(s) or portion thereof shall be deemed an unsafe condition, in accordance with Section 115.1.1. Components or portions thereof determined to be unsafe shall be repaired or replaced to conform to that code under which the building was constructed, remodeled or altered or this chapter, as deemed appropriate by the fire code official.

Where the condition of components is such that any building, structure or portion thereof presents an imminent danger to the occupants of the building, structure or portion thereof, the fire code official shall act in accordance with Section 115.2.

SECTION 702—DEFINITIONS

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

DRAFTSTOP.

FIREBLOCKING.

MEMBRANE-PENETRATION FIRESTOP SYSTEM.

OPENING PROTECTIVE.

SMOKE BARRIER.

SMOKE PARTITION.

THROUGH-PENETRATION FIRESTOP SYSTEM.

2025 CALIFORNIA FIRE CODE 7-3

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

FIRE AND SMOKE PROTECTION FEATURES

SECTION 703—PENETRATIONS

703.1 Maintaining protection. Materials and firestop systems used to protect membrane and through penetrations in fire-resistance-rated construction and construction installed to resist the passage of smoke shall be maintained. The materials and firestop systems shall be securely attached to or bonded to the construction being penetrated with no openings visible through or into the cavity of the construction. Where the system design number is known, the system shall be inspected to the listing criteria and manufacturer’s installation instructions.

703.2 Repair of penetrations. Where damaged, materials used to protect membrane- and through-penetrations shall be replaced or restored with materials or systems that meet or exceed the code requirements applicable at the time when the assembly was constructed, remodeled or altered.

SECTION 704—JOINTS AND VOIDS

704.1 Maintaining protection. Where required when the building was originally constructed, materials and systems used to protect joints and voids in the following locations shall be maintained. The materials and systems shall be securely attached to or bonded to the adjacent construction, without openings visible through the construction.
1. Joints in or between fire-resistance-rated walls, floors or floor/ceiling assemblies and roof or roof/ceiling assemblies.
2. Joints in smoke barriers.
3. Voids at the intersection of a horizontal floor assembly and an exterior curtain wall.
4. Voids at the intersection of a horizontal smoke barrier and an exterior curtain wall.
5. Voids at the intersection of a nonfire-resistance-rated floor assembly and an exterior curtain wall.
6. Voids at the intersection of a vertical fire barrier and an exterior curtain wall.
7. Voids at the intersection of a vertical fire barrier and a nonfire-resistance-rated roof assembly.
Unprotected joints and voids do not need to be protected where such joints and voids were not required to be protected when the building was originally constructed. Where the system design number is known, the system shall be inspected to the listing criteria and manufacturer’s installation instructions.
CFC § 705.10 High relevance — show source text
705.10 Joints. Joints made in or between exterior walls required by this section to have a fire-resistance rating shall comply with Section 715.

Exception: Joints in exterior walls that are permitted to have unprotected openings.

705.10.1 Voids. The void created at the intersection of a floor/ceiling assembly and an exterior curtain wall assembly shall be protected in accordance with Section 715.4.

705.11 Ducts and air transfer openings. Penetrations by air ducts and air transfer openings in fire-resistance-rated exterior walls required to have protected openings shall comply with Section 717.

Exception: Foundation vents installed in accordance with this code are permitted.

705.12 Parapets. Parapets shall be provided on exterior walls of buildings.

Exceptions: A parapet need not be provided on an exterior wall where any of the following conditions exist:
1. The wall is not required to be fire-resistance rated in accordance with Table 705.5 because of fire separation distance.
2. The building has an area of not more than 1,000 square feet (93 m [2] ) on any floor.
3. Walls that terminate at roofs of not less than 2-hour fire-resistance-rated construction or where the roof, including the deck or slab and supporting construction, is constructed entirely of noncombustible materials.
4. One-hour fire-resistance-rated exterior walls that terminate at the underside of the roof sheathing, deck or slab, provided that: 4.1. Where the roof/ceiling framing elements are parallel to the walls, such framing and elements supporting such framing shall not be of less than 1-hour fire-resistance-rated construction for a width of 4 feet (1220 mm) for Groups R and U and 10 feet (3048 mm) for other occupancies, measured from the interior side of the wall. 4.2. Where roof/ceiling framing elements are not parallel to the wall, the entire span of such framing and elements supporting such framing shall not be of less than 1-hour fire-resistance-rated construction. 4.3. Openings in the roof shall not be located within 5 feet (1524 mm) of the 1-hour fire-resistance-rated exterior wall for Groups R and U and 10 feet (3048 mm) for other occupancies, measured from the interior side of the wall. 4.4. The entire building shall be provided with not less than a Class B roof covering.
5. In Groups R-2 and R-3 where the entire building is provided with a Class C roof covering, the exterior wall shall be permitted to terminate at the underside of the roof sheathing or deck in Types III, IV and V construction, provided that one or both of the following criteria is met: 5.1. The roof sheathing or deck is constructed of approved noncombustible materials or of fire-retardant-treated wood for a distance of 4 feet (1220 mm). 5.2. The roof is protected with 0.625-inch (16 mm) Type X gypsum board directly beneath the underside of the roof sheathing or deck, supported by not less than nominal 2-inch (51 mm) ledgers attached to the sides of the roof framing members for a minimum distance of 4 feet (1220 mm).
6. Where the wall is permitted to have not less than 25 percent of the exterior wall areas containing unprotected openings based on fire separation distance as determined in accordance with Section 705.9.
CFC § 903.3.1.1 High relevance — show source text
Such openings shall be separated vertically not less than 3 feet (914 mm) by spandrel girders, exterior walls or other similar assemblies that have a fireresistance rating of not less than 1 hour, rated for exposure to fire from both sides, or by flame barriers that extend horizontally not less than 30 inches (762 mm) beyond the exterior wall. Flame barriers shall have a fire-resistance rating of not less than 1 hour. The unexposed surface temperature limitations specified in ASTM E119 or UL 263 shall not apply to the flame barriers unless otherwise required by the provisions of this code.

Exceptions:
1. This section shall not apply to buildings that are three stories or less above grade plane.
2. This section shall not apply to buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2.
7-10 2025 CALIFORNIA BUILDING CODE

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

FIRE AND SMOKE PROTECTION FEATURES
1. Open parking garages. 705.9.6 Vertical exposure. For buildings on the same lot, opening protectives having a fire protection rating of not less than [3] / 4 hour shall be provided in every opening that is less than 15 feet (4572 mm) vertically above the roof of an adjacent building or structure based on assuming an imaginary line between them. The opening protectives are required where the fire separation distances from the imaginary line to each building or structure are less than 15 feet (4572 mm).
Exceptions:
1. Opening protectives are not required where the roof assembly of the adjacent building or structure has a fire-resistance rating of not less than 1 hour for a minimum distance of 10 feet (3048 mm) from the exterior wall facing the imaginary line and the entire length and span of the supporting elements for the fire-resistance-rated roof assembly has a fire-resistance rating of not less than 1 hour.
2. Buildings on the same lot and considered as portions of one building in accordance with Section 705.3 are not required to comply with Section 705.9.6.
705.10 Joints. Joints made in or between exterior walls required by this section to have a fire-resistance rating shall comply with Section 715.

Exception: Joints in exterior walls that are permitted to have unprotected openings.

705.10.1 Voids. The void created at the intersection of a floor/ceiling assembly and an exterior curtain wall assembly shall be protected in accordance with Section 715.4.

705.11 Ducts and air transfer openings. Penetrations by air ducts and air transfer openings in fire-resistance-rated exterior walls required to have protected openings shall comply with Section 717.

Exception: Foundation vents installed in accordance with this code are permitted.

705.12 Parapets. Parapets shall be provided on exterior walls of buildings.

Exceptions: A parapet need not be provided on an exterior wall where any of the following conditions exist:
1. The wall is not required to be fire-resistance rated in accordance with Table 705.5 because of fire separation distance.
2. The building has an area of not more than 1,000 square feet (93 m [2] ) on any floor.
3. Walls that terminate at roofs of not less than 2-hour fire-resistance-rated construction or where the roof, including the deck or slab and supporting construction, is constructed entirely of noncombustible materials.
CFC § 708.5 High relevance — show source text
708.5 Exterior walls. Where exterior walls serve as a part of a required fire-resistance-rated separation, such walls shall comply with the requirements of Section 705 for exterior walls, and the fire-resistance-rated separation requirements shall not apply.

Exception: Exterior walls required to be fire-resistance rated in accordance with Section 1021.2 for exterior egress balconies, Section 1023.7 for interior exit stairways and ramps and Section 1027.6 for exterior exit stairways and ramps.

708.6 Openings. Openings in a fire partition shall be protected in accordance with Section 716.

708.7 Penetrations. Penetrations of fire partitions shall comply with Section 714.

708.8 Joints. Joints made in or between fire partitions shall comply with Section 715.

708.9 Ducts and air transfer openings. Penetrations in a fire partition by ducts and air transfer openings shall comply with Section 717.

SECTION 709—SMOKE BARRIERS

709.1 General. Vertical and horizontal smoke barriers shall comply with this section.

709.2 Materials. Smoke barriers shall be of materials permitted by the building type of construction.

2025 CALIFORNIA BUILDING CODE 7-17

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

FIRE AND SMOKE PROTECTION FEATURES

709.3 Fire-resistance rating. A 1-hour fire-resistance rating is required for smoke barriers.

Exception: Smoke barriers constructed of minimum 0.10-inch-thick (2.5 mm) steel in Group I-3 buildings.

709.4 Continuity. Smoke barriers shall form an effective membrane continuous from the top of the foundation or floor/ceiling assembly below to the underside of the floor or roof sheathing, deck or slab above, including continuity through concealed spaces, such as those found above suspended ceilings, and interstitial structural and mechanical spaces. The supporting construction shall be protected to afford the required fire-resistance rating of the wall or floor supported in buildings of other than Type IIB, IIIB or VB construction. Smoke-barrier walls used to separate smoke compartments shall comply with Section 709.4.1. Smoke-barrier walls used to enclose areas of refuge in accordance with Section 1009.6.4 or to enclose elevator lobbies in accordance with Section 405.4.3, 3007.6.2, or 3008.6.2 shall comply with Section 709.4.2.

Exception: Smoke-barrier walls are not required in interstitial spaces where such spaces are designed and constructed with ceilings or exterior walls that provide resistance to the passage of fire and smoke equivalent to that provided by the smoke-barrier walls.

709.4.1 Smoke-barrier assemblies separating smoke compartments. Smoke-barrier assemblies used to separate smoke compartments shall form an effective membrane enclosure that is continuous from an outside wall or smoke barrier wall to an outside wall or another smoke barrier wall and to the horizontal assemblies.
CFC § 1023.3.1. High relevance — show source text
1. Openings shall not be limited to 156 square feet (15 m [2] ) or an aggregate width of 25 percent of the length of the wall where the opening protective is a fire door assembly in a fire barrier separating an enclosure for exit access stairways and ramps, and interior exit stairways and ramps from an exit passageway in accordance with Section 1023.3.1.
2. Openings providing entrance to an elevator car shall not be limited to 156 square feet (15 m [2] ) or an aggregate width of 25 percent of the length of the wall where the opening protective is a fire door assembly in a fire barrier that is an elevator hoistway enclosure.
3. Openings shall not be limited to an aggregate width of 25 percent of the length of the wall where opening serves a shaft enclosure in accordance with Section 713.
4. Openings shall not be limited to an aggregate width of 25 percent of the length of the wall where opening serves a chute access room in accordance with Section 713.13.3 or a chute discharge room in accordance with Section 713.13.4.
707.7 Penetrations. Penetrations of fire barriers shall comply with Section 714.

707.7.1 Prohibited penetrations. Penetrations into enclosures for shafts, interior exit stairways and ramps, and exit passageways shall be allowed only where permitted by Sections 713.8.1, 1023.5 and 1024.6, respectively.

707.8 Joints. Joints made in or between fire barriers, and joints made at the intersection of fire barriers with the underside of a fireresistance-rated floor or roof sheathing, slab or deck above, and with other fire-resistance-rated wall assemblies shall comply with Section 715.

707.9 Voids at intersections. The voids created at the intersection of a fire barrier and a nonfire-resistance-rated roof assembly or a nonfire-resistance-rated exterior wall assembly shall comply with Section 715.

707.10 Ducts and air transfer openings. Penetrations in a fire barrier by ducts and air transfer openings shall comply with Section 717.

SECTION 708—FIRE PARTITIONS

708.1 General. The following wall assemblies shall comply with this section:
1. Separation walls as required by Section 420.2 for Group R occupancies.
2. Walls separating tenant spaces in covered and open mall buildings as required by Section 402.4.2.1.
3. Corridor walls as required by Section 1020.2 and in Group I-2 as required by Section 407.3.
4. Enclosed elevator lobby separation as required by Section 3006.3.
5. Egress balconies as required by Section 1021.2
6. Walls separating ambulatory care facilities from adjacent spaces, corridors or tenants as required by Section 422.2.
7. Walls separating dwelling and sleeping units in Groups R-1 and R-2 in accordance with Sections 907.2.8.1 and 907.2.9.1.
8. Vestibules in accordance with Section 1028.2.
9. Walls separating enclosed tenant spaces in high-rise buildings and in buildings of Types I, IIA, IIIA, IV or VA construction of Group A, E, H, I, L and R-2.1 occupancies and other applications listed in Section 1.11 regulated by the Office of the State Fire Marshal.

708.2 Materials. The walls shall be of materials permitted by the building type of construction.
CFC § 909.4.7 High relevance — show source text
[F] 909.4.7 Smoke control system interaction. The design shall consider the interaction effects of the operation of multiple smoke control systems for all design scenarios.

[F] 909.5 Smoke barrier construction. Smoke barriers required for passive smoke control and a smoke control system using the pressurization method shall comply with Section 709. The maximum allowable leakage area shall be the aggregate area calculated using the following leakage area ratios:
1. Walls A/A w = 0.00100
2. Interior exit stairways and ramps and exit passageways: A/A w = 0.00035
3. Enclosed exit access stairways and ramps and all other shafts: A/A w = 0.00150
4. Floors and roofs: A/A F = 0.00050
where:

A = Total leakage area, square feet (m [2] ). A F = Unit floor or roof area of barrier, square feet (m [2] ). A w = Unit wall area of barrier, square feet (m [2] ).

The leakage area ratios shown do not include openings due to gaps around doors and operable windows. The total leakage area of the smoke barrier shall be determined in accordance with Section 909.5.1 and tested in accordance with Section 909.5.2.

[F] 909.5.1 Total leakage area. Total leakage area of the barrier is the product of the smoke barrier gross area multiplied by the allowable leakage area ratio, plus the area of other openings such as gaps around doors and operable windows.

[F] 909.5.2 Testing of leakage area. Compliance with the maximum total leakage area shall be determined by achieving the minimum air pressure difference across the barrier with the system in the smoke control mode for mechanical smoke control systems utilizing the pressurization method. Compliance with the maximum total leakage area of passive smoke control systems shall be verified through methods such as door fan testing or other methods, as approved by the fire code official.

[F] 909.5.3 Opening protection. Openings in smoke barriers shall be protected by automatic-closing devices actuated by the required controls for the mechanical smoke control system. Door openings shall be protected by fire door assemblies complying with Section 716.

Exceptions:
1. Passive smoke control systems with automatic-closing devices actuated by spot-type smoke detectors listed for releasing service installed in accordance with Section 907.3. When used in Group I-2, such detectors shall activate the fire alarm system and shall close all the smoke barrier doors within the effected zone.
2. Fixed openings between smoke zones that are protected utilizing the airflow method in other than Group I-2.
3. In Group I-2, R-2.1 and ambulatory care facilities, where a pair of opposite-swinging doors are installed across a corridor in accordance with Section 909.5.3.1, the doors shall be protected in accordance with Section 716. The doors shall not have a center mullion. Positive-latching devices are required. Doors installed across corridors shall comply with Section 1010.1.1.
CFC § 722.2.2.1.3 High relevance — show source text
FIGURE 722.2.2.1.3—SLABS WITH RIBBED OR UNDULATING SOFFITS

For SI: 1 inch = 25.4 mm.

722.2.2.1.4 Flat plate concrete slabs with uniformly spaced hollow voids. Table 722.2.2.1 shall be used to determine the 1- and 2-hour fire-resistance ratings for flat plate concrete slabs with uniformly spaced hollow voids. The equivalent thickness of the slab shall be determined by dividing the net concrete volume of the slab by the floor area. The net concrete volume of the slab shall be equal to the volume of concrete of a solid slab minus the average concrete volume displaced by the hollow voids.

7-70 2025 CALIFORNIA BUILDING CODE

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

FIRE AND SMOKE PROTECTION FEATURES

722.2.2.2 Multicourse floors. The fire-resistance ratings of floors that consist of a base slab of concrete with a topping (overlay) of a different type of concrete shall comply with Figure 722.2.2.2.

FIGURE 722.2.2.2—FIRE-RESISTANCE RATINGS FOR TWO-COURSE CONCRETE FLOORS

For SI: 1 inch = 25.4 mm.

722.2.2.3 Multicourse roofs. The fire-resistance ratings of roofs that consist of a base slab of concrete with a topping (overlay) of an insulating concrete or with an insulating board and built-up roofing shall comply with Figures 722.2.2.3(1) and 722.2.2.3(2).

FIGURE 722.2.2.3(1)—FIRE-RESISTANCE RATINGS FOR CONCRETE ROOF ASSEMBLIES

For SI: 1 inch = 25.4 mm.

2025 CALIFORNIA BUILDING CODE 7-71

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

FIRE AND SMOKE PROTECTION FEATURES

FIGURE 722.2.2.3(2)—FIRE-RESISTANCE RATINGS FOR CONCRETE ROOF ASSEMBLIES

For SI: 1 inch = 25.4 mm.

722.2.2.3.1 Heat transfer. For the transfer of heat, three-ply built-up roofing contributes 10 minutes to the fire-resistance rating. The fire-resistance rating for concrete assemblies such as those shown in Figure 722.2.2.3(1) shall be increased by 10 minutes. This increase is not applicable to those shown in Figure 722.2.2.3(2).

722.2.2.4 Joints in precast slabs. Joints between adjacent precast concrete slabs need not be considered in calculating the slab thickness provided that a concrete topping not less than 1 inch (25 mm) thick is used. Where concrete topping is not used, joints must be grouted to a depth of not less than one-third the slab thickness at the joint, but not less than 1 inch (25 mm), or the joints must be made fire resistant by other approved methods.

722.2.3 Concrete cover over reinforcement. The minimum thickness of concrete cover over reinforcement in concrete slabs, reinforced beams and prestressed beams shall comply with this section.

|TABLE 722.2.3(1)—COVER

Frequently asked questions

What is a “listed” fire‑resistant joint system?

A “listed” system is one tested and published by a recognized testing/listing organization with an assigned fire‑resistance rating or leakage performance; the code requires installing listed systems in accordance with the listing and manufacturer instructions. § 715.2.1.

Do I need to upgrade joints in an old building that were not required when built?

No — unprotected joints and voids that were not required to be protected when the building was originally constructed need not be retrofitted; however any protection that was required originally must be maintained. § 704.1.

How is leakage measured for smoke‑barrier joints?

Leakage is measured per the referenced air‑leakage test protocol (the code references UL 2079 for joints in smoke barriers) and the system’s L rating must not exceed 5 cfm per linear foot at 0.30 in. w.g. for ambient and elevated tests. § 715.9.

If a joint system is damaged, what must be done?

Materials/systems used to protect joints and voids must be replaced or restored with materials or systems that meet or exceed the code requirements that applied when the assembly was constructed, remodeled or altered. § 704.2.

Are there width‑based exceptions for control joints?

Yes — control joints that do not exceed 0.625 inch (15.9 mm) and have been tested appropriately are an exception to the fire‑resistant joint system requirement. See the exception list in § 715.3.

Ask about the CFC

Get cited, plain-English answers on the California Fire Code for your project — any code section, any scenario.

Start Free Trial

Related in the CFC

How must through‑penetrations be protected in fire‑resistance‑rated construction?

What are the requirements for fire‑ and smoke‑protected doors, windows and fire‑rated glazing?

Openings, penetrations and joints (firestop, opening protectives)

California Fire Code