What is the correct relationship between a fire stopping material and the barrier it penetrates?

• A. Equal to the barrier's fire resistance rating
• B. Greater than the barrier's rating
• C. Less than the barrier's rating
• D. Not related to the barrier's rating

Answer: (A)

Fire stopping material is used to restore the fire resistance of a barrier at penetrations. The firestop system and the barrier are tested as an assembly, and the overall fire resistance is governed by the weakest component. To maintain the barrier’s rated performance across the opening, the fire stopping material must be rated to the same duration as the barrier. If the firestop were rated lower, the penetration would weaken the whole assembly and drop the rating. If it were rated higher, it wouldn’t harm the barrier, but the effective rating would still be that of the barrier. So the proper relationship is that the fire stopping material is equal to the barrier’s fire resistance rating.