Housewrap vs. Felt

Nearly 20 years ago, plastic housewrap burst onto the building scene with the introduction of Dupont's Tyvek. Since that time, Tyvek and a host of imitators have become standard materials, and are displacing tar paper in much the same way that plywood displaced board sheathing. Housewraps were originally marketed chiefly as air infiltration barriers, but since these materials are commonly used instead of felt paper, they are also relied upon as weather barriers. This means that in addition to preventing outside air from leaking through, the housewrap also has to keep out any rainwater or snowmelt that finds its way behind the siding. The plastic wraps are touted for another