BCAB #1776 - Moisture Protection for Interior Finishes, Article 18.104.22.168.
December 17, 2015
Re: Moisture Protection for Interior Finishes, Article 22.214.171.124.
The project is a single family residential building that falls within Part 9 of the BC Building Code. The building has a basement that is partially below grade. Wood frame walls are proposed to be constructed 1.5” away from the interior of the concrete basement walls. The wood frame wall will be insulated with batt insulation between the studs and finished with gypsum board. The exterior of the concrete basement wall below grade will be dampproofed with a tar coating.
Reason for Appeal
There is a disagreement on whether the proposed interior wall is protected from moisture as required by Article 126.96.36.199. “Moisture Protection for Interior Finishes” of the BC Building Code.
The appellant contends that the proposed wall is protected from moisture by the 1.5” air gap and that it complies with Article 188.8.131.52. There is no finish applied to the concrete wall, nor wood in contact with the concrete wall as described in Sentence (1) of this Article, therefore no membrane or coating is required by Sentence 184.108.40.206.(2).
Local Authority’s Position
The building official maintains that the proposed basement wall assembly does not comply Article 220.127.116.11. Because an insulation value of R 17 is required in this climate zone, compliant batt insulation installed between the studs would be in contact with the wall.
Appeal Board Decision #1776
Although the use of batt insulation in this assembly may place the insulation in contact with the concrete foundation wall, such installation is not prohibited by Subsection 9.25.2. or Article 18.104.22.168. of the BC Building Code.
The scope of Article 22.214.171.124. is primarily limited to interior finishes applied directly to a concrete wall below grade, or where wood members are placed in contact with a concrete wall below grade. Neither are the case of the circumstances of this Appeal.
Therefore it is the determination of the Board that the proposed assembly is exempt from the requirements of Article 126.96.36.199.
Lyle Kuhnert, Chair