Code Reference
ArchitecturalIBC 2021

Section Table 601/Fire-Resistance Rating Requirements

IBC Table 601 establishes minimum fire-resistance ratings for structural elements based on construction type.

What this section requires

Table 601 specifies fire-resistance ratings in hours for building elements based on the construction type (Types IA, IB, IIA, IIB, IIIA, IIIB, IV, VA, VB). Ratings range from 0 hours (Type VB) to 3 hours (Type IA structural frame). The table covers the structural frame, bearing walls (exterior and interior), nonbearing exterior walls, floor construction, and roof construction.

Why this section exists

Fire-resistance ratings ensure that structural elements maintain their integrity during a fire for long enough to allow occupant evacuation and firefighter operations. Higher-risk buildings (larger, taller, more occupants) require higher construction types with greater fire resistance. The construction type, determined by Table 601, cascades into nearly every other fire protection decision in the building design.

What plan reviewers look for

Plan reviewers verify that the construction type stated on the drawings matches the fire-resistance ratings shown for structural elements in the wall sections, floor assemblies, and structural details. They check that every rated assembly references a tested design (UL, GA, or other listing) and that the rating meets or exceeds the minimum from Table 601.

Common violations

Construction type does not match ratings shown
The cover sheet states Type IIA construction (1-hour structural frame) but the structural details show unprotected steel members, which is Type IIB. The stated construction type must match the actual fire protection provided.
Floor assembly rating insufficient
A Type IIIA building requires 1-hour floor construction, but the floor assembly detail shows an unrated assembly or references a listing with insufficient rating.
Roof rating omitted
The roof construction fire-resistance rating is not addressed in the drawings. While many construction types allow 0-hour roofs, this must be verified against Table 601 and documented.
Compliance tip
State the construction type prominently on the cover sheet and general notes. For each rated assembly (structural frame, bearing walls, floors), reference the specific UL or GA assembly number that achieves the required rating. Include a fire-resistance rating matrix on the drawings showing each element and its required and provided rating.

Related IBC requirements

Section 602 defines the five construction types. Table 602 covers exterior wall fire-resistance requirements based on fire separation distance. Section 706 covers fire wall requirements. Chapter 7 as a whole addresses fire-resistance-rated construction.

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Related sections

602.2Types of ConstructionIBC 2021706.1Fire WallsIBC 2021Table 602Exterior Wall Fire-Resistance RatingsIBC 2021

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