December 15, 2011
BCAB #1704
Re: Minor Combustible Components, Article 3.1.5.2.
Project Description
The project is an unsprinklered highrise building of residential occupancy. The building and the exterior wall assembly are of noncombustible construction.
Reason for Appeal
Within the exterior noncombustible wall assembly, it is proposed to use combustible fiberglass spacers.
Appellant's Position
The appellant contends that the fiberglass spacers can be considered similar minor combustible components per clause 3.1.5.2.(1)(h) as the combustibility and exposure would be similar or less than is permitted by Article 3.1.5.5. for wood blocking or foamed plastic air sealants. Further, Article 3.1.5.5. is not applicable because the cladding is noncombustible.
Building Official's Position
The building official maintains that the thermal spacers are not minor combustible components per Article 3.1.5.2. as they support a significant envelope component.
Further, sentence 3.1.5.5 requires non-loadbearing exterior wall assemblies incorporating combustible components to be tested to CAN/CSA S134. The thermal spacer is a combustible component in such a wall assembly. No such test has been provided.
Appeal Board Decision #1704
It is the determination of the Board that the fiberglass spacers are similar minor components per clause 3.1.5.2.(1)(h). Further, the Board determines that it is the intent of the code that the requirements of Article 3.1.5.5. do not apply to similar minor components permitted by Article 3.1.5.2.
George Humphrey, Chair