BCAB #1241 - Vapour Barrier; Article 22.214.171.124.
March 27, 1991
Re: Vapour Barrier; Article 126.96.36.199.
Residential wood frame construction.
Reason for Appeal
Article 188.8.131.52. requires a vapour barrier to "protect the entire insulated wall surface."
The appellant does not feel the intent of Article 184.108.40.206. is to require the vapour barrier to be installed in the rim joist area (the spaces between the ends of the floor joists).
Building Official's Position
The building official contends that the rim joist area must be protected with a vapour barrier because shrinkage in the large number of joints would allow significant amounts of moisture to enter the structure. The building official cites Appendix item A-9.26.5 which states, in part, that "attention must be made to less obvious leakage paths such as ...... wall-ceiling intersections and gaps created by shrinkage of framing members."
Appeal Board Decision #1241
The Board considers Article 220.127.116.11. is clear in requiring a vapour barrier over the entire insulated wall surface. The rim joist / box joist area is part of the insulated wall surface and a vapour barrier is required.
George R. Humphrey, Chair