Section Table 602/Exterior Wall Fire-Resistance Ratings
IBC Table 602 establishes exterior wall ratings and opening limitations based on fire separation distance from the property line.
Exterior walls must have a fire-resistance rating based on the fire separation distance (FSD) from the lot line or the centerline of a public way. At less than 5 feet FSD, exterior walls require a 1-hour rating for most occupancies (2 hours for Group H) with no unprotected openings permitted. At 5 to 10 feet, reduced ratings apply with limited openings. At 10 to 30 feet, openings are limited by percentage. Beyond 30 feet, no rating or opening limitations apply. The ratings are for the exterior face only (fire exposure from outside).
Why this section exists
Exterior wall ratings prevent fire from spreading between adjacent buildings through radiation and direct flame impingement. A building fire close to the property line radiates heat onto the neighboring building's exterior wall. Without adequate fire resistance, the neighboring wall can fail and the fire can spread to the adjacent building. Closer to the property line requires higher ratings because the radiant heat exposure is more intense.
What plan reviewers look for
Plan reviewers measure the fire separation distance from the building face to the property line (or centerline of a public way) on the site plan. They look up the required rating from Table 602 based on the FSD, construction type, and occupancy. They check that exterior wall assemblies have the required rating and that openings (windows, doors) comply with the percentage limitations or are protected with fire-rated assemblies.
Common violations
Related IBC requirements
Table 601 covers structural fire-resistance ratings by construction type. Section 705 covers the exterior wall requirements in detail. Section 716 covers opening protectives for rated walls. Section 602 covers construction type definitions that affect the Table 602 lookup.