As important to a home as insulation.
With more than 30 years of residential performance on millions of homes, Tyvek® HomeWrap® is the world's leading housewrap. Wrapping a home in a protective envelope is a good building practice that helps combat a home's worst enemies: water, moisture and air infiltration. Tyvek® behind a home's siding is an excellent secondary defense against the weather.

What is HomeWrap®?
Tyvek® HomeWrap® is a weatherization membrane that provides a protective layer under a home's siding and over the sheathing. It is literally wrapped around a home over the wood or foam sheathing, cut out around windows and doors and taped at the seams.

The unique, nonwoven-fiber structure of Tyvek® HomeWrap® resists air infiltration and water intrusion, yet is engineered to readily allow moisture vapor to diffuse through the sheet, helping prevent mold and mildew buildup and wood rot. The fibrous structure is engineered with microscopic pores that readily allow moisture vapor to evaporate but are so small that bulk water and air cannot penetrate. Siding, whether it's vinyl, wood, stucco, brick, or composite, does not completely prevent air and water penetration. Tyvek® is designed as a secondary defense to help manage a home's wall systems.

A good weather resistive barrier (WRB) housewrap has 4 equally important functions:

1. It MUST have a high level of air resistance - to help prevent drafts, reduce energy bills and resist the flow of moisture laden air though wall cavities.
2. It MUST have a high level of water resistance - to help protect the wall cavity from water that gets behind the cladding.
3. It MUST have moderate to high vapor permeability - to promote drying in wall systems.
4. It MUST be durable -to withstand the rigors of the construction site and continue to perform once construction is completed.