Theresa Ann Weston

The Implications of Durability, Resilience and Energy Efficiency on the Advancement of Water Management in Wall Assemblies

As building, energy, and green codes become more stringent, new building technologies and innovations are being incorporated into the building envelope. When incorporating new technologies into building assemblies, traditional construction practices need to be adapted. However, as these adaptations of construction practices take place, they still need to maintain adherence to basic principles of water management to prevent moisture accumulation in building assemblies. A critical component of water management is water-resistive barriers. Water-resistive barriers are used in light-frame wall assemblies behind the cladding to control the ingress of water, which penetrates the cladding, and keep it from penetrating further into the wall. Traditional water-resistive barriers were asphalt-impregnated papers and felts, which were applied in shingle fashion over the wall studs or sheathing. Plastic building wraps have to a large extent replaced the traditional building papers, comprising 75 % of the U.S. housing market. Recently, new materials being used as water-resistive barriers include panel materials and fluid-applied coatings. Assessing the durability of water-resistive barriers has been complicated by this range of material types. Because of the shingle-fashion installation, durability assessment of traditional materials and building wraps has focused on the material durability. The new materials require additional durability assessments relating to compatibility and durability of adhesion, most importantly at panel and substrate joints. This article describes the framework for evaluating water-resistive barrier durability.