Commercial Building Inspector B2Wall Construction and Wall CoveringsEasy
A commercial building inspector is evaluating the fire-stopping at a penetration through a 1-hour fire-resistance-rated wood-framed wall. The penetration is for a noncombustible metallic pipe. What is the minimum required fire-resistance rating for the fire-stopping material around this penetration?
- A1-hour
- B1 1/2-hour
- C2-hour
- D1/2-hour
Show answer & explanationAnswer & explanation
Correct answer: A. 1-hour
According to IBC Section 714.3.1.2, through-penetrations in fire-resistance-rated walls shall be protected by an approved fire-resistant joint system or fire-stopping material installed in accordance with Section 714.3.1.2, which requires the fire-stopping to have a rating not less than the required rating of the assembly being penetrated. Therefore, for a 1-hour wall, the fire-stopping must be 1-hour.
Why the other options are wrong
- B. 1 1/2-hour is greater than required, an overdesign.
- C. 2-hour is greater than required, an overdesign.
- D. 1/2-hour is insufficient for a 1-hour rated assembly.
Fire-Stopping Rating (Through-Penetrations)
Fire-stopping materials used for through-penetrations in fire-resistance-rated assemblies must have a fire-resistance rating equal to or greater than the assembly they penetrate to maintain compartmentalization.
- Matches the rating of the penetrated assembly.
- Prevents spread of fire and smoke.
- Applies to pipes, conduits, cables, etc.
- Governed by IBC Section 714.3.1.2.
Memory trick: Penetration's Protection: Rating Reflects Resistance.