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CMHC commissioned this project to quantify the air leakage characteristics of the header joist, the electrical outlets and the window opening in wood-frame walls. Three construction methods currently employed to achieve airtightness were evaluated: the sealed membrane approach where polyethylene sheet and sealant provide the air barrier; the external air barrier approach which uses a continuous vapour permeable membrane sandwiched between two layers of external wall sheathing and the airtight drywall approach in which the interior gypsum board, framing materials and gaskets are used as the air barrier. To provide a reference for comparison, the traditional approach to wood-frame wall construction was also evaluated.
All but the traditional panels and the airtight drywall approach in which the interior gypsum board, framing materials and gaskets are used as the air barrier. To provide a reference for comparison, the traditional approach to wood-frame wall construction was also evaluated.
All but the traditional panels and the airtight drywall approach (ADA) electrical outlet panel exceeded the current airtightness standards for glass and aluminum curtain walls, but only the ADA window panel met a suggested goal proposed by NRC researchers. All but three could be used to construct walls of houses intended to meet airtightness standards of the R-2000 program. However, the window detail appears to offer the greatest potential for increasing overall house airtightness. | 