Any of several spun-fiber polyolefin rolled sheet goods for wrapping the exterior of the building envelope. Touted as an air barrier that can "breathe" with respect to water in the vapor phase but repel water in the liquid state, its properties do NOT include uni-directional vapor permeability, and its properties in comparison to traditional asphalt-impregnated building paper must be carefully considered when designing exterior wall profiles.
Housewrap is a sheet of plastic, often fiber-reinforced, that is used to reduce air leakage in new homes. These sheets are wrapped around the outside of a house during construction. Builders must seal the housewrap at all joints and seams to create a truly continuous, effective air retarder.
Any of the numerous spun-fiber polyolefin rolled sheet goods, or perforated plastic films designed to function as drainage planes.