The fluid-applied air barrier (FAAB) concept was originally a Canadian-developed technology from more than 40 years ago. Back in the early 1970s, the genesis was an adhesive combining air- and vapor-retarding characteristics—eventually, this material would find its way into building codes.
When specifying and installing air and moisture/vapor barriers, consideration is often given to cold-weather limitations of those materials to better ensure proper application and long-term performance.
At this point, most design/construction professionals have a pretty good understanding of the need for well-designed air and moisture control layers in wall assemblies. Water-resistive barriers (WRBs) have been in use for decades; in more recent years, a number of new systems have popped up that combine these products with an air barrier function.
Industry codes are tightening the building envelope and increasing the required R-value of walls. This is a good thing for energy savings and thermal comfort. Yet, one change to a building’s system sets forth a series of other changes. The tight-envelope construction techniques to which architects and builders are now required to adhere have led to a steep reduction in air movement through walls.
Over the years, there has been a tremendous amount of innovation in the building industry—still, the ability to achieve a waterproof wall system still eludes design/construction professionals. If the wall is not properly designed, this moisture will remain trapped causing numerous issues, such as the corrosion of structural reinforcing, and the proliferation of rot and mold.