Code Reference
ArchitecturalIBC 2021

Section 1020.1/Corridor Fire-Resistance Rating

IBC 1020 establishes when corridors must be fire-resistance rated based on occupancy and sprinkler protection.

What this section requires

Corridors serving as part of the means of egress must have fire- resistance-rated walls as specified in Table 1020.1. In Group H and I occupancies, corridors require a 1-hour rating regardless of sprinkler protection. In Group A, B, E, F, M, S, and U occupancies, corridors require a 1-hour rating without sprinklers but have no rating requirement when the building is fully sprinklered (with exceptions). In Group R occupancies, corridors require a 1-hour rating (0.5-hour if sprinklered). Corridor walls must extend from the floor to the underside of the floor or roof deck above.

Why this section exists

Corridors are the primary exit access paths that occupants use to reach exits. If a fire in an adjacent room breaches the corridor wall, the corridor fills with smoke and heat, blocking the egress path for everyone else on that floor. Fire-rated corridor walls contain the fire long enough for occupants to evacuate through the corridor. Sprinklered buildings receive reduced or eliminated corridor ratings because the sprinkler system controls the fire before it breaches the corridor walls.

What plan reviewers look for

Plan reviewers check the floor plan for corridor wall ratings based on Table 1020.1. They verify the occupancy group and sprinkler status to determine the required rating. They check that corridor walls extend to the structure above (not just to the ceiling grid). They verify that doors in rated corridors have the correct fire-protection rating (typically 20 minutes for 1-hour corridors).

Common violations

Corridor walls not extended to structure
Rated corridor walls terminate at the suspended ceiling grid instead of extending to the underside of the floor or roof deck above. The space above the ceiling allows fire and smoke to bypass the corridor wall.
Rating required but not shown
A non-sprinklered Group B building does not show corridor wall fire ratings on the floor plan. Without sprinklers, a 1-hour corridor rating is required per Table 1020.1.
Non-rated door in rated corridor wall
A standard hollow-metal door without a fire-protection rating is shown in a 1-hour corridor wall. Doors in rated corridors require a 20-minute fire-protection rating with self-closing hardware.
Compliance tip
Indicate corridor wall fire ratings on the floor plan with a clear legend. Reference Table 1020.1 and the occupancy/sprinkler basis. Show corridor wall construction extending to the deck above in wall sections. Specify fire-rated door assemblies at all openings in rated corridors.

Related IBC requirements

Section 1005 covers egress width. Section 1006 covers the number of exits required. Section 706 covers fire barriers (higher-rated walls). Section 716 covers opening protectives (doors in rated walls). Section 1018 covers corridor width requirements.

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Related sections

706.1Fire WallsIBC 20211005.1Minimum Egress WidthIBC 20211006.2Minimum Number of ExitsIBC 2021