CBC · California Building Code

Protection of floor/roof assemblies, vertical openings and shaft enclosures

The CBC requires floors and roofs to be continuous without vertical holes unless the opening is protected by a listed method in Section 712 (for example, located inside a properly constructed shaft). Shafts that protect vertical openings must meet construction, material and fire‑resistance requirements in Section 713 (including minimum 1‑ or 2‑hour ratings depending on how many stories the shaft connects). Special rules (like tested access panels, restrained lay‑in ceilings, and escalator shutters) and limits on openings are set out in § 711, § 712 and § 713 and must be followed exactly to maintain the assembly ratings and protect occupants filefile.

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Last reviewed: July 5, 2026

What the code requires — 2-4 sentences

The California Building Code requires horizontal (floor/roof) assemblies to be continuous and free of vertical openings except where specific protection methods are used (§ 711 and § 711.2) . Vertical openings must be protected by one of the methods listed in Section 712 (for example, placement inside an approved shaft enclosure, limited two‑story openings, protected escalator openings, or tested horizontal fire doors) (§ 712.1) . When a vertical opening is protected by a shaft enclosure, that enclosure must meet the construction, continuity and minimum fire‑resistance ratings set out for shafts in Section 713 (including general requirements in § 713.1) .

Requirements in detail

Horizontal assemblies (floor/roof) — continuity and rating

  • Horizontal assemblies must be continuous without vertical openings except where permitted by Section 712 (§ 711.2.2) .
  • Fire‑resistance ratings for horizontal assemblies depend on the separation function (mixed occupancies, fire areas, dwelling/sleeping unit separations, smoke barriers, etc.) and must meet the minimums in § 711.2.4 and the building type requirements (§ 711.2.4.1–.6) .
  • Lay‑in ceiling panels used as part of a rated horizontal assembly must be restrained against an upward force of 1 psf; wire or approved devices are required where panel weight alone is inadequate (§ 711.2.5) .

Vertical openings — permitted protection methods (high‑level)

Section 712 requires that each vertical opening comply with one of the listed protection methods (§ 712.1). Selected methods and key limits include:

  • Shaft enclosure — vertical openings entirely inside a shaft enclosure complying with Section 713 (§ 712.1.1) .
  • Openings entirely within an individual dwelling unit (≤ 4 stories) may be unconcealed and permitted (§ 712.1.2) .
  • Escalator openings permitted with sprinkler/draft curtain protection or automatic shutters; shutters must be noncombustible, 1.5‑hour rated and meet listed operational requirements (§ 712.1.3 & § 712.1.3.2) .
  • Two‑story openings (subject to several restrictions) are permitted in many occupancies (§ 712.1.9) .
  • Floor fire doors and access doors in rated horizontal assemblies are permitted when tested/listed for the application (§ 712.1.13, § 712.1.13.1–.2) .

Shaft enclosures — construction, continuity, openings and ratings

  • Scope/general: Section applies to shafts required to protect openings and penetrations in floor/ceiling and roof/ceiling assemblies; interior exit stairways/ramps are governed separately (§ 713.1) .
  • Construction: Shaft enclosures must be built as fire barriers (see § 707) or as horizontal assemblies (see § 711), or both (§ 713.2) .
  • Materials: Shaft enclosure materials are limited to those permitted by the building type of construction (§ 713.3) .
  • Fire‑resistance rating: Minimum ratings are tied to the number of stories the shaft connects — 2 hours where connecting four stories or more; 1 hour where connecting less than four stories. The shaft must be at least the rating of the penetrated floor assembly but need not exceed 2 hours (with a specific exception for certain high‑rise reductions) (§ 713.4) .
  • Openings and penetrations: Openings must be protected per opening protectives rules; doors must be self‑ or automatic‑closing by smoke detection where required. Penetrations must be protected per the penetration provisions (e.g., § 714) and prohibited unless necessary for the shaft function (§ 713.7–713.8.1) .
  • Continuity and joints: Shafts must meet continuity requirements of fire barriers or horizontal assemblies as applicable (§ 713.5) and joint rules (§ 713.9) .

Decision‑relevant numeric values (summary table)

Item Value / limit Code Reference
Upward design force for lay‑in ceiling panel restraint 1.0 lb/ft² (48 Pa) § 711.2.5
Shaft fire‑resistance rating — connecting ≥ 4 stories Not less than 2 hours (includes basements) § 713.4
Shaft fire‑resistance rating — connecting < 4 stories Not less than 1 hour § 713.4
Maximum required shaft rating relative to floor assembly Shaft rating ≥ floor assembly rating, but need not exceed 2 hours § 713.4
Escalator automatic shutter minimum rating 1.5 hours (and noncombustible; listed) § 712.1.3.2 (item 2)
Two‑story opening limits (general) Does not connect >2 stories; various occupancy and concealment restrictions § 712.1.9
Access doors in rated ceilings — test standard ASTM E119 or UL 263 as horizontal assemblies; labeled § 712.1.13.2

Exceptions & special cases

  • High‑rise reduction: Section 713.4 contains an exception allowing reduced shaft fire‑resistance ratings in some high‑rise building conditions per § 403.2.1.2; check that section when designing shafts in high‑rise buildings (§ 713.4 Exception) .
  • Dwelling unit vertical openings: Vertical openings entirely within a single dwelling unit that connect four stories or fewer may be left unconcealed/unenclosed (i.e., permitted) (§ 712.1.2) .
  • Skylights: Skylights and similar penetrations through a fire‑resistance‑rated roof deck may be unprotected provided the structural integrity of the rated assembly is maintained; however, unprotected skylights are not permitted where the roof is required to be rated per § 705.9.6 (§ 712.1.15) .
  • Shafts that do not extend to the bottom/top of the building: Section 713 provides alternative compliance paths (enclose at lowest/top level by rated construction, terminate in a specially separated room, or protect with listed fire dampers) and lists relevant exceptions (§ 713.11–713.12) .

Common mistakes

  • Assuming any vertical hole through a floor is permitted. Many openings are allowed only if they comply with one of the specific methods in § 712.1 (shaft enclosure, two‑story opening limits, tested doors, escalator protections, etc.) — do not rely on general practice; identify the specific § 712.1 method and证 label/listing required .
  • Underrating shaft enclosures. Designers sometimes pick the floor assembly rating and forget to apply the 2‑hour minimum when the shaft connects four or more stories — § 713.4 sets clear minimums and the shaft must be at least the floor rating, up to 2 hours .
  • Improper ceiling panel securement. For rated floor/ceiling or roof/ceiling assemblies that use lay‑in panels, failing to provide wire or approved restraint when panel weight is insufficient to resist 1 psf upward force violates § 711.2.5 .
  • Leaving penetrations/unprotected openings in shafts. Penetrations are limited to those necessary for the shaft function and must be protected per the penetration rules; nonessential penetrations and openings are prohibited (§ 713.7–713.8.1) .
  • Relying on non‑listed horizontal fire doors / access panels. Floor fire doors and access doors in rated horizontal assemblies must be tested and labeled (NFPA 288 or ASTM E119/UL 263 as applicable) — see § 712.1.13.1–.2 .

Worked example — applying the rules with numbers

Scenario: An office building has a mechanical shaft that passes through five stories (including a basement) and penetrates a 1‑hour rated floor/ceiling assembly on each level. The shaft will contain ductwork and occasional maintenance access doors.

How to apply the CBC rules:

  1. Because the shaft connects four stories or more (five stories including basement), § 713.4 requires the shaft enclosure to have a fire‑resistance rating of not less than 2 hours .
  2. The code also requires the shaft enclosure fire rating to be not less than the floor assembly penetrated; here the floor assembly is 1 hour, so the shaft rating must be at least 1 hour — but the 2‑hour minimum governs because of story count (§ 713.4) .
  3. Construct the shaft as a fire barrier per § 713.2 (or as required horizontal assemblies per § 711) and ensure materials are allowed for the building construction type (§ 713.2–713.3) .
  4. Protect any openings into the shaft (access doors, discharge openings) with listed opening protectives per § 713.7 and with self‑ or automatic‑closing by smoke detection where required (§ 713.7) .
  5. Duct and air transfer penetrations must comply with the duct opening/penetration rules (see § 713.10 referencing § 717) and any required dampers or listed assemblies must be provided (§ 713.10) . Result: Provide a continuous 2‑hour shaft enclosure built with permitted materials, labeled opening protectives on access/discharge doors, and listed protection for duct/penetration points to comply with §§ 711/712/713 requirements above file.

Related provisions

  • § 711 — Floor and Roof Assemblies (horizontal assembly continuity, ratings)
  • § 711.2 — Horizontal assemblies (materials, continuity, supporting construction, specific rating rules)
  • § 712 — Vertical Openings (allowed protection methods and limits)
  • § 713 — Shaft Enclosures (construction, materials, openings, penetrations, ratings and continuity)
  • § 714 — Penetrations (protection of through‑penetrations and membrane penetrations — applicable to penetrations in shafts and horizontals)
  • § 716 — Opening Protectives (required for openings into shafts and horizontal assemblies)
  • § 717 — Ducts and Air Transfer Openings (requirements for ducts penetrating shaft enclosures)

Code references

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

  • CBC § 712.1.12 High relevance — show source text

    712.1.12 Exit access stairways and ramps. Vertical openings containing exit access stairways or ramps in accordance with Section 1019 shall be permitted.

    712.1.13 Openings. Vertical openings for floor fire doors and access doors shall be permitted where protected by Section 712.1.13.1 or 712.1.13.2.

    712.1.13.1 Horizontal fire door assemblies. Horizontal fire door assemblies used to protect openings in fire-resistance-rated horizontal assemblies shall be tested in accordance with NFPA 288, and shall achieve a fire-resistance rating not less than the assembly being penetrated. Horizontal fire door assemblies shall be labeled by an approved agency. The label shall be permanently affixed and shall specify the manufacturer, the test standard and the fire-resistance rating.

    712.1.13.2 Access doors. Access doors shall be permitted in ceilings of fire-resistance-rated floor/ceiling and roof/ceiling assemblies, provided that such doors are tested in accordance with ASTM E119 or UL 263 as horizontal assemblies and labeled by an approved agency for such purpose.

    712.1.14 Group I-3. In Group I-3 occupancies, vertical openings shall be permitted in accordance with Section 408.5.

    712.1.15 Skylights. Skylights and other penetrations through a fire-resistance-rated roof deck or slab are permitted to be unprotected, provided that the structural integrity of the fire-resistance-rated roof assembly is maintained. Unprotected skylights shall not be permitted in roof assemblies required to be fire-resistance rated in accordance with Section 705.9.6. The supporting construction shall be protected to afford the required fire-resistance rating of the horizontal assembly supported.

    712.1.16 Openings otherwise permitted. Vertical openings shall be permitted where allowed by other sections of this code.

    SECTION 713—SHAFT ENCLOSURES

    713.1 General. The provisions of this section shall apply to shafts required to protect openings and penetrations through floor/ceiling and roof/ceiling assemblies. Interior exit stairways and ramps shall be enclosed in accordance with Section 1023.

    713.2 Construction. Shaft enclosures shall be constructed as fire barriers in accordance with Section 707 or horizontal assemblies in accordance with Section 711, or both.

    713.3 Materials. Shaft enclosures shall be of materials permitted by the building type of construction.

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    713.4 Fire-resistance rating. Shaft enclosures shall have a fire-resistance rating of not less than 2 hours where connecting four stories or more, and not less than 1 hour where connecting less than four stories. The number of stories connected by the shaft enclosure shall include any basements but not any mezzanines. Shaft enclosures shall have a fire-resistance rating not less than the floor assembly penetrated, but need not exceed 2 hours. Shaft enclosures shall meet the requirements of Section 703.2.1.1.

    Exception: Shafts having a reduced fire-resistance rating in high-rise buildings in accordance with Section 403.2.1.2.

  • CBC § 711.2.5 High relevance — show source text

    711.2.5 Ceiling panels. Where the weight of lay-in ceiling panels, used as part of fire-resistance-rated floor/ceiling or roof/ceiling assemblies, is not adequate to resist an upward force of 1 pound per square foot (48 Pa), wire or other approved devices shall be installed above the panels to prevent vertical displacement under such upward force.

    711.2.6 Unusable space. In 1-hour fire-resistance-rated floor/ceiling assemblies, the ceiling membrane is not required to be installed over unusable crawl spaces. In 1-hour fire-resistance-rated roof assemblies, the floor membrane is not required to be installed where unusable attic space occurs above.

    711.3 Nonfire-resistance-rated floor and roof assemblies. Nonfire-resistance-rated floor, floor/ceiling, roof and roof/ceiling assemblies shall comply with Sections 711.3.1 and 711.3.2.

    711.3.1 Materials. Assemblies shall be of materials permitted by the building type of construction.

    711.3.2 Continuity. Assemblies shall be continuous without vertical openings, except as permitted by Section 712.

    SECTION 712—VERTICAL OPENINGS

    712.1 General. Each vertical opening shall comply in accordance with one of the protection methods in Sections 712.1.1 through 712.1.16.

    712.1.1 Shaft enclosures. Vertical openings contained entirely within a shaft enclosure complying with Section 713 shall be permitted.

    712.1.2 Individual dwelling unit. Unconcealed vertical openings totally within an individual residential dwelling unit and connecting four stories or less shall be permitted.

    712.1.3 Escalator openings. Where a building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, vertical openings for escalators shall be permitted where protected in accordance with Section 712.1.3.1 or 712.1.3.2.

    712.1.3.1 Opening size. Protection by a draft curtain and closely spaced sprinklers in accordance with NFPA 13 shall be permitted where the area of the vertical opening between stories does not exceed twice the horizontal projected area of the escalator. In other than Groups B and M, this application is limited to openings that do not connect more than four stories.

    712.1.3.2 Automatic shutters. Protection of the vertical opening by listed or approved shutters at every penetrated floor shall be permitted in accordance with all of the following:

    1. The shutter shall be installed in accordance with the manufacturer’s instructions.

    2. The shutter shall be of noncombustible construction and have a fire-resistance rating of not less than 1.5 hours.

    3. The shutter shall close immediately upon the actuation of a smoke detector installed in accordance with Section 907.3.

    4. The shutter shall completely close off the vertical opening.

    5. Escalators shall cease operation when the shutter begins to close.

    6. The shutter shall operate at a speed of not more than 30 feet per minute (152.4 mm/s).

    7. The shutter shall be equipped with a sensing leading edge to stop closure where in contact with any obstacle, and continue to close when the obstacle is cleared.

    712.1.4 Penetrations. Penetrations, concealed and unconcealed, shall be permitted where protected in accordance with Section 714.

    712.1.5 Joints. Joints shall be permitted where complying with Section 712.1.5.1 or 712.1.5.2, as applicable.

  • CBC § 712.1.16 High relevance — show source text

    712.1.16 Openings otherwise permitted. Vertical openings shall be permitted where allowed by other sections of this code.

    SECTION 713—SHAFT ENCLOSURES

    713.1 General. The provisions of this section shall apply to shafts required to protect openings and penetrations through floor/ceiling and roof/ceiling assemblies. Interior exit stairways and ramps shall be enclosed in accordance with Section 1023.

    713.2 Construction. Shaft enclosures shall be constructed as fire barriers in accordance with Section 707 or horizontal assemblies in accordance with Section 711, or both.

    713.3 Materials. Shaft enclosures shall be of materials permitted by the building type of construction.

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    713.4 Fire-resistance rating. Shaft enclosures shall have a fire-resistance rating of not less than 2 hours where connecting four stories or more, and not less than 1 hour where connecting less than four stories. The number of stories connected by the shaft enclosure shall include any basements but not any mezzanines. Shaft enclosures shall have a fire-resistance rating not less than the floor assembly penetrated, but need not exceed 2 hours. Shaft enclosures shall meet the requirements of Section 703.2.1.1.

    Exception: Shafts having a reduced fire-resistance rating in high-rise buildings in accordance with Section 403.2.1.2.

    713.5 Continuity. Shaft enclosures shall be constructed as fire barriers in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both, and shall have continuity in accordance with Section 707.5 for fire barriers or Section 711.2.2 for horizontal assemblies, as applicable.

    713.6 Exterior walls. Where exterior walls serve as a part of a required shaft enclosure, such walls shall comply with the requirements of Section 705 for exterior walls and the fire-resistance-rated enclosure 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.

    713.7 Openings. Openings in a shaft enclosure shall be protected in accordance with Section 716 as required for fire barriers. Doors shall be self- or automatic-closing by smoke detection in accordance with Section 716.2.6.6.

    713.7.1 Prohibited openings. Openings other than those necessary for the purpose of the shaft shall not be permitted in shaft enclosures.

    713.8 Penetrations. Penetrations in a shaft enclosure shall be protected in accordance with Section 714 as required for fire barriers or horizontal assemblies or both. Structural elements, such as beams or joists, where protected in accordance with Section 714 shall be permitted to penetrate a shaft enclosure.

    713.8.1 Prohibited penetrations. Penetrations other than those necessary for the purpose of the shaft shall not be permitted in shaft enclosures.

    Exception: Membrane penetrations shall be permitted on the outside of shaft enclosures. Such penetrations shall be protected in accordance with Section 714.4.2.

    713.9 Joints. Joints in a shaft enclosure shall comply with Section 715.

  • CBC § 707.6 High relevance — show source text

    707.6 Openings. Openings in a fire barrier shall be protected in accordance with Section 716. Openings shall be limited to a maximum aggregate width of 25 percent of the length of the wall, and the maximum area of any single opening shall not exceed 156 square feet (15 m [2] ). Openings in enclosures for shafts, interior exit stairways and ramps and exit passageways shall also comply with Sections 713.7, 1023.4 and 1024.5, respectively.

    Exceptions:

    1. Openings shall not be limited to 156 square feet (15 m [2] ) where adjoining floor areas are equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
    2. 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 serving enclosures for exit access stairways and ramps, and interior exit stairways and ramps.

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    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 has been tested in accordance with ASTM E119 or UL 263 and has a minimum fire-resistance rating not less than the fire-resistance rating of the wall.

    2. Fire window assemblies permitted in atrium separation walls shall not be limited to a maximum aggregate width of 25 percent of the length of the wall.

    3. 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.

    4. 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.

    5. 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.

    6. 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.

  • CBC § 1206.6.2 High relevance — show source text

    4. In Group I-2 occupancies, in other than rooms containing stationary fuel cell power systems required to be separated per California Fire Code Section 1206.6.2, fire barriers required by Section 509.4 shall be permitted to terminate at an individu- ally protected structural member in the same plane, provided the structural member has a solid web or solid surface along its length for the full height of the structural member and has a fire-resistance rating of not less than that required for the fire barrier wall.

    5. In Group I-2 occupancies, in other than rooms containing stationary fuel cell power systems required to be separated per California Fire Code Section 1206.6.2, fire barrier separations required by Section 509.4 that do not extend to the underside of the roof sheathing.

    707.5.1 Supporting construction. The supporting construction for a fire barrier shall be protected to afford the required fireresistance rating of the fire barrier supported. Hollow vertical spaces within a fire barrier shall be fireblocked in accordance with Section 718.2 at every floor level.

    Exceptions:

    1. The maximum required fire-resistance rating for assemblies supporting fire barriers separating tank storage as provided for in Section 415.9.1.2 shall be 2 hours, but not less than required by Table 601 for the building construction type.
    2. Supporting construction for 1-hour fire barriers required by Table 509.1 in buildings of Types IIB, IIIB and VB construction is not required to be fire-resistance rated unless required by other sections of this code.

    707.6 Openings. Openings in a fire barrier shall be protected in accordance with Section 716. Openings shall be limited to a maximum aggregate width of 25 percent of the length of the wall, and the maximum area of any single opening shall not exceed 156 square feet (15 m [2] ). Openings in enclosures for shafts, interior exit stairways and ramps and exit passageways shall also comply with Sections 713.7, 1023.4 and 1024.5, respectively.

    Exceptions:

    1. Openings shall not be limited to 156 square feet (15 m [2] ) where adjoining floor areas are equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
    2. 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 serving enclosures for exit access stairways and ramps, and interior exit stairways and ramps.

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    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 has been tested in accordance with ASTM E119 or UL 263 and has a minimum fire-resistance rating not less than the fire-resistance rating of the wall.
    2. Fire window assemblies permitted in atrium separation walls shall not be limited to a maximum aggregate width of 25 percent of the length of the wall.
  • CBC § 713.10 High relevance — show source text

    713.10 Duct and air transfer openings. Penetrations of a shaft enclosure by ducts and air transfer openings shall comply with Section 717.

    713.11 Enclosure at the bottom. Shafts that do not extend to the bottom of the building or structure shall comply with one of the following:

    1. Be enclosed at the lowest level with construction of the same fire-resistance rating as the lowest floor through which the shaft passes, but not less than the rating required for the shaft enclosure.

    2. Terminate in a room having a use related to the purpose of the shaft. The room shall be separated from the remainder of the building by fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both. The fire-resistance rating and opening protectives shall be not less than the protection required for the shaft enclosure.

    3. Be protected by approved fire dampers installed in accordance with their listing at the lowest floor level within the shaft enclosure.

    Exceptions:

    1. The fire-resistance-rated room separation is not required, provided that the only openings in or penetrations of the shaft enclosure to the interior of the building occur at the bottom. The bottom of the shaft shall be closed off around the penetrating items with materials permitted by Section 718.3.1 for draftstops, or the room shall be provided with an approved automatic sprinkler system.
    2. A shaft enclosure containing a waste or linen chute shall not be used for any other purpose and shall discharge in a room protected in accordance with Section 713.13.4.
    3. The fire-resistance-rated room separation and the protection at the bottom of the shaft are not required provided that there are no combustibles in the shaft and there are no openings or other penetrations through the shaft enclosure to the interior of the building.

    713.12 Enclosure at top. The top of shaft enclosures shall comply with one of the following:

    1. Extend to the underside of the roof sheathing, deck or slab of the building, and the roof assembly shall comply with the requirements for the type of construction as specified in Table 601.
    2. Terminate below the roof assembly and be enclosed at the top with construction of the same fire-resistance rating as the topmost floor penetrated by the shaft, but not less than the fire-resistance rating required for the shaft enclosure.
    3. Extend past the roof assembly and comply with the requirements of Section 1511.

    713.12.1 Penthouse mechanical rooms. A fire/smoke damper shall not be required at the penetration of the rooftop structure where shaft enclosures extend up through the roof assembly into a rooftop structure conforming to Section 1511. Ductwork in the shaft shall be connected directly to HVAC equipment.

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    713.13 Waste, recycling and linen chutes and incinerator rooms. Waste, recycling and linen chutes shall comply with the provisions of NFPA 82, Chapter 6 and shall meet the requirements of Sections 712 and 713.13.1 through 713.13.6. Incinerator rooms shall meet the provisions of Sections 713.13.4 and 713.13.5.

    Exception: Chutes serving and contained within a single dwelling unit.

  • 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 § 713.12 High relevance — show source text

    713.12 Enclosure at top. The top of shaft enclosures shall comply with one of the following:

    1. Extend to the underside of the roof sheathing, deck or slab of the building, and the roof assembly shall comply with the requirements for the type of construction as specified in Table 601.
    2. Terminate below the roof assembly and be enclosed at the top with construction of the same fire-resistance rating as the topmost floor penetrated by the shaft, but not less than the fire-resistance rating required for the shaft enclosure.
    3. Extend past the roof assembly and comply with the requirements of Section 1511.

    713.12.1 Penthouse mechanical rooms. A fire/smoke damper shall not be required at the penetration of the rooftop structure where shaft enclosures extend up through the roof assembly into a rooftop structure conforming to Section 1511. Ductwork in the shaft shall be connected directly to HVAC equipment.

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    713.13 Waste, recycling and linen chutes and incinerator rooms. Waste, recycling and linen chutes shall comply with the provisions of NFPA 82, Chapter 6 and shall meet the requirements of Sections 712 and 713.13.1 through 713.13.6. Incinerator rooms shall meet the provisions of Sections 713.13.4 and 713.13.5.

    Exception: Chutes serving and contained within a single dwelling unit.

    713.13.1 Waste, recycling and linen chute enclosures. A shaft enclosure containing a recycling, waste or linen chute shall not be used for any other purpose and shall be enclosed in accordance with Section 713.4. A shaft enclosure shall be permitted to contain recycling and waste chutes. Openings into the shaft, from access rooms and discharge rooms, shall be protected in accordance with this section and Section 716. Openings into chutes shall not be located in corridors. Doors into chutes shall be selfclosing. Discharge doors shall be self-or automatic-closing upon the actuation of a smoke detector in accordance with Section 716.2.6.6, except that heat-activated closing devices shall be permitted between the shaft and the discharge room.

    713.13.2 Materials. A shaft enclosure containing a waste, recycling, or linen chute shall be constructed of materials as permitted by the building type of construction.

    713.13.3 Chute access rooms. Access openings for waste, recycling or linen chutes shall be located in rooms or compartments enclosed by not less than 1-hour fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both. Openings into the access rooms shall be protected by opening protectives having a fire protection rating of not less than [3] / 4 hour. Doors shall be self- or automatic-closing upon the detection of smoke in accordance with Section 716.2.6.6. The room or compartment shall be configured to allow the access door to the room or compartment to close and latch with the access panel to the chute in any position.

    713.13.4 Chute discharge room. Waste, recycling or linen chutes shall discharge into an enclosed room separated by fire barriers with a fire-resistance rating not less than the required fire rating of the shaft enclosure and constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both.

  • CBC § 713.6 High relevance — show source text

    713.6 Exterior walls. Where exterior walls serve as a part of a required shaft enclosure, such walls shall comply with the requirements of Section 705 for exterior walls and the fire-resistance-rated enclosure 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.

    713.7 Openings. Openings in a shaft enclosure shall be protected in accordance with Section 716 as required for fire barriers. Doors shall be self- or automatic-closing by smoke detection in accordance with Section 716.2.6.6.

    713.7.1 Prohibited openings. Openings other than those necessary for the purpose of the shaft shall not be permitted in shaft enclosures.

    713.8 Penetrations. Penetrations in a shaft enclosure shall be protected in accordance with Section 714 as required for fire barriers or horizontal assemblies or both. Structural elements, such as beams or joists, where protected in accordance with Section 714 shall be permitted to penetrate a shaft enclosure.

    713.8.1 Prohibited penetrations. Penetrations other than those necessary for the purpose of the shaft shall not be permitted in shaft enclosures.

    Exception: Membrane penetrations shall be permitted on the outside of shaft enclosures. Such penetrations shall be protected in accordance with Section 714.4.2.

    713.9 Joints. Joints in a shaft enclosure shall comply with Section 715.

    713.10 Duct and air transfer openings. Penetrations of a shaft enclosure by ducts and air transfer openings shall comply with Section 717.

    713.11 Enclosure at the bottom. Shafts that do not extend to the bottom of the building or structure shall comply with one of the following:

    1. Be enclosed at the lowest level with construction of the same fire-resistance rating as the lowest floor through which the shaft passes, but not less than the rating required for the shaft enclosure.

    2. Terminate in a room having a use related to the purpose of the shaft. The room shall be separated from the remainder of the building by fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both. The fire-resistance rating and opening protectives shall be not less than the protection required for the shaft enclosure.

    3. Be protected by approved fire dampers installed in accordance with their listing at the lowest floor level within the shaft enclosure.

    Exceptions:

    1. The fire-resistance-rated room separation is not required, provided that the only openings in or penetrations of the shaft enclosure to the interior of the building occur at the bottom. The bottom of the shaft shall be closed off around the penetrating items with materials permitted by Section 718.3.1 for draftstops, or the room shall be provided with an approved automatic sprinkler system.
    2. A shaft enclosure containing a waste or linen chute shall not be used for any other purpose and shall discharge in a room protected in accordance with Section 713.13.4.
    3. The fire-resistance-rated room separation and the protection at the bottom of the shaft are not required provided that there are no combustibles in the shaft and there are no openings or other penetrations through the shaft enclosure to the interior of the building.
  • CBC § 408.5 High relevance — show source text

    408.5 Protection of vertical openings. Any vertical opening shall be protected by a shaft enclosure in accordance with Section 713, or shall be in accordance with Section 408.5.1.

    408.5.1 Floor openings. The open space in front of a cell tier and connected chases, not exceeding two tiers in height, shall not be considered a vertical shaft and need not meet the fire-resistive shaft enclosure requirements of Section 713.

    408.5.2 Shaft openings in communicating floor levels. Where a floor opening is permitted between communicating floor levels of a housing unit in accordance with Section 408.5.1, plumbing chases serving vertically stacked individual cells contained with the housing unit shall be permitted without a shaft enclosure.

    [BE] 408.6 Smoke barrier. Occupancies in Group I-3 shall have smoke barriers complying with Sections 408.6 and 709 to divide every story occupied by residents for sleeping, or any other story having an occupant load of 50 or more persons, into not fewer than two smoke compartments.

    Exception: Spaces having a direct exit to one of the following, provided that the locking arrangement of the doors involved complies with the requirements for doors at the smoke barrier for the use condition involved:

    1. A public way.
    2. A building separated from the resident housing area by a 2-hour fire-resistance-rated assembly or 50 feet (15 240 mm) of

    open space. 3. A secured yard or court having a holding space 50 feet (15 240 mm) from the housing area that provides 6 square feet (0.56 m [2] ) or more of refuge area per occupant, including residents, staff and visitors. 4. Holding facility.

    [BE] 408.6.1 Smoke compartments. The number of residents in any smoke compartment shall be not more than 200. The distance of travel to a door in a smoke barrier from any room door required as exit access shall be not greater than 150 feet (45 720 mm). The distance of travel to a door in a smoke barrier from any point in a room shall be not greater than 200 feet (60 960 mm).

    Exception: The travel distance may be increased by 50 feet from areas open only to the staff.

    [BE] 408.6.2 Refuge area. Not less than 6 net square feet (0.56 m [2] ) per occupant shall be provided on each side of each smoke barrier for the total number of occupants in adjoining smoke compartments. This space shall be readily available wherever the occupants are moved across the smoke barrier in a fire emergency.

    [BE] 408.6.3 Independent egress. A means of egress shall be provided from each smoke compartment created by smoke barriers without having to return through the smoke compartment from which means of egress originates.

    408.7 Security glazing. In occupancies in Group I-3, windows and doors in 1-hour fire barriers constructed in accordance with Section 707, fire partitions constructed in accordance with Section 708 and smoke barriers constructed in accordance with Section 709 shall be permitted to have security glazing installed provided that the following conditions are met.

    1. Individual panels of glazing shall not exceed 1,296 square inches (0.84 m [2] ).
    2. The glazing shall be protected on both sides by an automatic sprinkler system. The sprinkler system shall be designed to, when actuated, wet completely the entire surface of any glazing affected by fire.
  • CBC § 415.6.5. High relevance — show source text

    The aggregate quantity of pyrophoric gases in the building shall not exceed the amounts set forth in Table 415.6.5.
    f. Quantity of Class 3 water-reactive solids in a single tool shall not exceed 1 pound.|

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    [F] 415.11.1.2 Separation. Fabrication areas, whose sizes are limited by the quantity of hazardous materials allowed by Table 415.11.1.1, shall be separated from each other, from corridors and from other parts of the building by not less than 1-hour fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both.

    Exceptions:

    1. Doors within such fire barrier walls, including doors to corridors, shall be only self-closing fire door assemblies having a fire protection rating of not less than [3] / 4 hour.
    2. Windows between fabrication areas and corridors are permitted to be fixed glazing listed and labeled for a fire protection rating of not less than [3] / 4 hour in accordance with Section 716.

    [F] 415.11.1.3 Location of occupied levels. Occupied levels of fabrication areas shall be located at or above the first story above grade plane.

    [F] 415.11.1.4 Floors. Except for surfacing, floors within fabrication areas shall be of noncombustible construction.

    Openings through floors of fabrication areas are permitted to be unprotected where the interconnected levels are used solely for mechanical equipment directly related to such fabrication areas (see Section 415.11.1.5).

    Floors forming a part of an occupancy separation shall be liquid tight.

    [F] 415.11.1.5 Shafts and openings through floors. Elevator hoistways, vent shafts and other openings through floors shall be enclosed where required by Sections 712 and 713. Mechanical, duct and piping penetrations within a fabrication area shall not extend through more than two floors. The annular space around penetrations for cables, cable trays, tubing, piping, conduit or ducts shall be sealed at the floor level to restrict the movement of air. The fabrication area, including the areas through which the ductwork and piping extend, shall be considered to be a single conditioned environment.

    [F] 415.11.1.6 Ventilation. Mechanical exhaust ventilation at the rate of not less than 1 cubic foot per minute per square foot

    [0.0051 m [3] /(s × m [2] )] of floor area shall be provided throughout the portions of the fabrication area where HPM are used or stored. The exhaust air duct system of one fabrication area shall not connect to another duct system outside that fabrication area within the building.

    A ventilation system shall be provided to capture and exhaust gases, fumes and vapors at workstations.

    Two or more operations at a workstation shall not be connected to the same exhaust system where either one or the combination of the substances removed could constitute a fire, explosion or hazardous chemical reaction within the exhaust duct system.

    Exhaust ducts penetrating fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711 shall be contained in a shaft of equivalent fire-resistance-rated construction. Exhaust ducts shall not penetrate fire walls.

    Fire dampers shall not be installed in exhaust ducts.

  • CBC § 711.2.4.2 High relevance — show source text

    711.2.4.2 Separating fire areas. Where the horizontal assembly separates a single occupancy into different fire areas, the assembly shall have a fire-resistance rating of not less than that required by Section 707.3.10.

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    711.2.4.3 Dwelling units and sleeping units. Horizontal assemblies serving as dwelling or sleeping unit separations in accordance with Section 420.3 shall be not less than 1-hour fire-resistance-rated construction.

    Exception: Horizontal assemblies separating dwelling units and sleeping units shall be not less than [1] / 2 -hour fire-resistancerated construction in a building of Types IIB, IIIB and VB construction, where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.

    711.2.4.4 Separating smoke compartments. Where the horizontal assembly is required to be a smoke barrier, the assembly shall comply with Section 709.

    711.2.4.5 Separating incidental uses. Where the horizontal assembly separates incidental uses from the remainder of the building, the assembly shall have a fire-resistance rating of not less than that required by Section 509.

    711.2.4.6 Other separations. Where a horizontal assembly is required by other sections of this code, the assembly shall have a fire-resistance rating of not less than that required by that section.

    711.2.5 Ceiling panels. Where the weight of lay-in ceiling panels, used as part of fire-resistance-rated floor/ceiling or roof/ceiling assemblies, is not adequate to resist an upward force of 1 pound per square foot (48 Pa), wire or other approved devices shall be installed above the panels to prevent vertical displacement under such upward force.

    711.2.6 Unusable space. In 1-hour fire-resistance-rated floor/ceiling assemblies, the ceiling membrane is not required to be installed over unusable crawl spaces. In 1-hour fire-resistance-rated roof assemblies, the floor membrane is not required to be installed where unusable attic space occurs above.

    711.3 Nonfire-resistance-rated floor and roof assemblies. Nonfire-resistance-rated floor, floor/ceiling, roof and roof/ceiling assemblies shall comply with Sections 711.3.1 and 711.3.2.

    711.3.1 Materials. Assemblies shall be of materials permitted by the building type of construction.

    711.3.2 Continuity. Assemblies shall be continuous without vertical openings, except as permitted by Section 712.

    SECTION 712—VERTICAL OPENINGS

    712.1 General. Each vertical opening shall comply in accordance with one of the protection methods in Sections 712.1.1 through 712.1.16.

    712.1.1 Shaft enclosures. Vertical openings contained entirely within a shaft enclosure complying with Section 713 shall be permitted.

    712.1.2 Individual dwelling unit. Unconcealed vertical openings totally within an individual residential dwelling unit and connecting four stories or less shall be permitted.

Frequently asked questions

When is a vertical opening required to be enclosed in a shaft?

Any vertical opening that isn’t specifically permitted under another method in § 712 must be enclosed in a shaft complying with § 713; § 712.1 lists the allowed alternatives and § 713.1 identifies the shaft‑enclosure scope file.

What minimum fire‑resistance rating must a shaft have?

A shaft connecting four stories or more must have at least a 2‑hour rating; one connecting fewer than four stories must have at least a 1‑hour rating. The shaft must be at least the rating of the floor assembly it penetrates but need not exceed 2 hours except where other code sections allow reductions (§ 713.4) .

Can I put lay‑in ceiling panels in a rated floor/ceiling ceiling without additional restraints?

Only if the weight of the panels alone resists an upward force of 1 lb/ft² (48 Pa). If not, wire or approved devices must be installed above the panels to prevent displacement per § 711.2.5 .

Are escalator openings treated differently?

Yes — escalator openings may be protected by draft curtains and closely spaced sprinklers (with size limits) or by automatic shutters that meet the listed operational and rating requirements (shutters must be noncombustible and 1.5‑hour rated) per § 712.1.3 and § 712.1.3.2 .

What must I do about ducts that pass through a shaft enclosure?

Duct and air transfer openings through a shaft must comply with § 717 as referenced from § 713.10; provide listed fire/smoke dampers or other listed protection where required by those duct/air‑transfer rules .

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