Resilience of Canadian residential brick veneer wall construction to climate change

Abstract

Canada employs a prescriptive-based code for residential buildings. The minimum requirements as prescribed in the 2015 National Building Code were developed based on historical climate which was assumed static. It is now evident that the climate is changing and it is anticipated that wind-driven rain events will be more frequent, of longer duration and of increased intensity. These changes may affect the durability of wall assemblies designed following the minimum requirements set in the building code. In this study, the moisture performance of residential wood-framed walls using brick veneer as cladding and meeting the minimum requirements of the National Building Code were evaluated for different climatic regions of Canada. Various types of brick veneer were evaluated using hygrothermal simulations and projected future climate loads. The mold growth index on the sheathing panel was used as performance indicator. Results showed that the future moisture performance of brick veneer walls depends on the brick properties and varies with climatic region. In particular, for brick veneer having relatively high water absorption coefficient and lower vapor permeability, there may be a heightened risk to mold growth in the future if used in locations on the east and west coasts of Canada. As consequence, the minimum requirements for brick veneer walls may need to be reviewed in these locations to ensure their long-term performance.