Commercial Building Inspector B2Roof Ceiling ConstructionMedium
A contractor is installing a new roof covering on a Type II-A commercial building. The roof deck consists of structural concrete. The chosen roof covering is a modified bitumen membrane system. According to IBC, what is the minimum required Class fire classification for this roof covering assembly?
- AClass B
- BClass A
- CClass C
- DNo classification required
Show answer & explanationAnswer & explanation
Correct answer: B. Class A
For Type I or II construction, which includes Type II-A, the IBC generally requires a Class A roof covering assembly. Structural concrete decks often contribute to a higher assembly rating, but the roof covering itself must meet the Class A requirement.
Why the other options are wrong
- A. Class B is for less fire-resistive construction types or specific conditions, not typically Type II-A.
- C. Class C is the lowest classification and is generally not permitted for commercial buildings of Type II-A construction.
- D. A fire classification is almost always required for roof coverings on commercial buildings, especially Type II-A.
Roof Covering Fire Classification (Type II-A)
The minimum fire classification required for roof coverings on Type II-A commercial buildings, which is Class A, indicating high fire resistance.
- Class A is highest rating.
- Required for Type I & II construction.
- Prevents flame propagation.
Memory trick: Building Type II-A, Class A roof must play, keeping fire away.