Leading building consultants for years have said that air leakage is the leading cause of exterior wall issues. Issues such as efflorescence, masonry spalls, ice build-up, frozen pipes, wall cavity condensation, high energy costs, and poor indoor humidity control have all been linked to air leakage. Air leakage occurs when voids, cracks, and holes in the building envelope form a continuous path from inside to outside and create an air pressure difference. Poor connections between the wall and roof and other openings, as well as cracks caused by thermal expansion or contraction, are known to compromise heating and cooling energy in the form of ex-filtrating and infiltrating air.
The need for a properly installed air barrier is obvious. Air barriers stop outside air from entering the building through the walls, windows and roof, and inside air from ex-filtrating through the building envelope to the outside. A study released in 2005 by the National Institute of Standards and Technology (NIST) indicated that HVAC energy savings from 15-40% could be achieved with increased air-tightness in the building envelope. The specification of an air barrier is critical to achieving the long-term performance goals of energy efficiency and indoor environmental quality and to ensure that code requirements are satisfied.
Contact the air and vapor barrier experts at Carlisle Coatings & Waterproofing for project specific questions, details and applications guidance. They may be reached at 888-229-2199 or [email protected] .
For straight-forward information about how new wall assemblies containing plastic foam insulation and combustible weather barriers can meet tough new NFPA 285 standards, please visit fireresistccw.com.