Housewrap your Homes Protective Layer

By: Terrance Quinn, CS CAPS, CGR

What is Housewrap?

House wrap is the plastic-based barrier used to help keep wind and water at bay while allowing water vapor to evaporate.


Tyvek Housewrap

What Should I knowabout it?

First, housewrap acts as a backup barrier that keeps water off the building sheathing and framing.

Second, housewrap serves as an air barrier to prevent infiltration of wind driven air which will help reduce heating and cooling costs.

Thirdly, housewrap provides a vapor-permeable membrane that allows moisture in the lumber to escape.

Are all housewrap products the same?    No, There are different housewraps designed for different  applicatioGreenGuard HouseWarpns.

Homewrap is the most common used on most wood framed homes.

Pinkwrap is a translucent membrane that makes it easy to see where to nail the siding.

Typar is guaranteed to be tear-resistant making it ideal for use under stucco or cedar siding.

StuccoWrap wont absorb water and has surface texture channels to remove water.

What is a Permenance rating?

Permeance ratings, reflect the measure of a materials ability to transfer water vapor. Materials with higher perm ratings essentially speed the escape of trapped moisture.

Some low-tech housewraps achieve their high perm rating with mechanically punched perforations in the membrane. These perforations increase the passage of water vapor, but they also make the housewrap more susceptible to bulk water leakage.

Remember many housewraps are good at resisting bulk water, but
they should not be considered waterproof. If you use tightly fastened board
siding or T-111 panels, any water trapped between the siding and a smooth
housewrap will sit and eventually could make its way through the housewrap and
into the framing.  In these cases it’s a good idea to choose a furrowed rain-screen housewrap. Its embossed texture provides just enough airspace for liquid water to drain away before it has a chance to penetrate the membrane.

Here’s the bottom line:

Installation is more important than material choice. No matter what brand of housewrap you choose, you will be wasting your money unless you install it properly and carefully.


CAT Exteriors specialized in exterior renovation projects (Siding, Roofing, Windows, Doors, & Decks) in Massachusetts South Shore Towns like Braintree, Weymouth, Holbrook, Randolph, Bridgewater (East & West), and Quincy MA.