Term: Housewrap

Any of the numerous artificial polymer rolled sheet goods designed to function as drainage planes, a class of sheathing membranes. Some are also used as part of an air barrier system. Can be made of spun-fiber polyolefin, perforated plastic films, or coated and micro-perforated polymers. Marketed as an air barrier that can “breathe” with respect to water in the vapor phase but repel liquid water, its properties do not include uni-directional vapor permeability. Builders should understand their region before determining how to use housewrap and other barriers, if any, before building.

Source: RR-0106: Problems with Housewraps