Developing Innovative Drainage and Drying Solutions for the Building Enclosure PDF

Residential building enclosures are experiencing water entrapment and deterioration of wood-based components, even with the use of water resistive barrier (WRB) materials required by national building codes. The purposes of this investigation were to: 1) Obtain qualitative information about water resistance performance of some absorptive claddings when tested in mock-ups built with OSB sheathing, commonly available WRBs, and common fasteners, in conjunction with a prototype furred WRB design approach (using pan flashing and closed cell foam plastic furring strips). 2) Obtain qualitative performance data on moisture management performance by the prototype furred WRB design approach when installed on dwellings in lieu of claddings that lacked drainage/drying features. Laboratory evaluations support the hypothesis that WRBs may not provide sufficient water penetration resistance without supplementary drainage provisions. Field evaluations provide support for the hypothesis that placing furred WRBs and sill pans in exterior walls may reduce the risk of consequential water intrusion into as-built residential construction.

Presented at Thermal Performance of Exterior Envelopes of Whole Buildings X – December 2007

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