What is a Water-Resistive Barrier (WRB)?
Builders install a variety of products on the exterior of foundations, above-grade walls, and roofs as water-resistive barriers (WRBs), required by the International Residential Code (IRC). Water-resistive barriers are also called weather-resistant barriers, but the former term is now considered preferable. WRBs are buildings’ last and primary exterior water barrier. WRBs vary widely in their vapor …