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.

Related terms: Drainage Plane, Sheathing Membrane, Air Control Layer System

Related resources: RR-0106: Problems with Housewraps, RR-0105: Brick, Stucco, Housewrap and Building Paper