Hygrothermal performance of RH-dependent vapour retarder in Canadian coastal climate

Tariku, Fitsum (Fitsum Tariku (Fitsum_Tariku)) (author)
Maref, Wahid (author)
Di Lenardo, Bruno (author)
Gatland, S. (author)
(editor)
(translator)

© 2009, F. Tariku, W. Maref, B. Di Lenardo, S. Gatland.

Proceedings of 12th Canadian Conference of Building Science and Technology: 06 May 2009, Montreal, QC. The hygrothermal performance of wood-frame wall with stucco cladding exposed to the coastal climate of Vancouver, BC, is studied. The primary objective of the study is to compare the moisture management performance of two vapour barriers: the relatively new SmartVapour Retarder (SVR) and commonly used Polyethylene sheet. For a reference purpose a wood-frame wall with no vapour barrier is considered as well. The performances of these three walls, which are exposed to the same indoor and outdoor climatic loads, are compared with respect to their dynamic responses to two simulation variables: interior moisture load (simulated water intrusion in the stud cavity) and paint on the interior gypsum board. The water intrusion is assumed to be through defect areas and the quantity is correlated with the amount of wind-driven rain that the wall is exposed to. The hygrothermal simulation results suggest that adoption of SVR as a vapour barrier yields better moisture management of the sheathing board (OSB) for any conditions considered in this paper including internal moisture load and interior paint. But, in coastal climate, it may have adverse effect on the moisture management of the interior gypsum board, in cases where water leaks into the cavity and the interior gypsum board is painted with low-vapour permeance paint.

http://nparc.cisti-icist.nrc-cnrc.gc.ca/eng/view/object/?id=0150a485-cc3...