Residential Building Inspector B1Building Planning and Life SafetyHard
A residential building inspector is reviewing plans for a new single-family dwelling that includes an under-stair storage area. This area is enclosed and located beneath a required exit stairway. What is the minimum fire-resistance rating required for the enclosure walls and ceiling of this storage area?
- A2-hour fire-resistance rating
- B0-hour fire-resistance rating
- C1/2-hour fire-resistance rating
- D1-hour fire-resistance rating
Show answer & explanationAnswer & explanation
Correct answer: D. 1-hour fire-resistance rating
Storage areas beneath exit stairways pose a significant fire risk, as they can compromise the egress path. The IRC requires a specific fire-resistance rating to protect this critical escape route.
Why the other options are wrong
- A. While providing more protection, 2-hour is not the minimum required for this specific enclosure.
- B. A 0-hour rating is inadequate for protecting an exit path.
- C. This rating is insufficient for an enclosure beneath a required exit stairway.
Under-Stair Storage Fire Rating
Enclosed storage areas beneath required exit stairways must have a minimum fire-resistance rating to protect the egress path from fire.
- Applies specifically to *required* exit stairways.
- Prevents fire in storage from compromising the exit route.
- Often achieved with fire-rated gypsum board.
Memory trick: Stairs for escape, storage below, one hour's a must, for safety's glow.