House Wrap Under Roof Sheathing

In this post we compared barricade wrap plus tyvek homewrap homeguard house wrap certainteed certawrap and the zip system.

House wrap under roof sheathing.

Plastic housewraps range from around 5 to over 50 perms. You can find a complete library of technical documents for the zip system at this link. The reason for this is the housewrap manufacterers instructions call out their own product not their competitors. The homes i built then still look brand new today.

I ve been using hardie siding in the texas heat for over 10 years. Seal all seams with a special tape provided by the house wrap manufacturer. It just a matter of careful detailing especially around doors windows and other joints prone to leakage. That keeps drafts from reaching your insulation and prevents heated and cooled air from seeping out through the walls.

Install house wrap before doors and windows. The other wrinkle is that when using zip sheathing very few manufactures include instructions for installation on that type of sheathing. The primary goal of a sheathing wrap or housewrap is to protect a building s structural components from water. It is literally wrapped around a building cut out around windows and doors and taped at the seams.

Depending on how it s hung house wrap can either act as a moisture or wind barrier. House wrap is a weatherization membrane which provides a protective layer under a building s siding and over the wall girts or sheathing. For instance protecto wrap flashing tape on tyvek. Most house wraps are weather resistant barriers wrbs that aim to prevent air and moisture infiltration to the wall system while protecting the sheathing.

At the same time the sheathing wrap must be permeable enough to allow drying to the building s exterior if the framing or sheathing should get wet. House wrap behind a building s siding is an excellent secondary defense against the weather. Traditional sheathing wraps such as asphalt felt and grade d building paper used under stucco both measure about 5 perms. Where you ll often see plywood used instead of osb is in roof sheathing where the risks of moisture and leaks are greater.

When used to slow winds its job is to seal gaps and leaks in the osb panels or plywood sheathing that makes up your home s exterior walls. General recommendations that usually apply to fabric type house wrap include. Work from the bottom up overlapping the lower courses. Hardiewrap weather barrier is installed over the sheathing beneath the exterior siding to reduce water and air infiltration.

In general a sheathing wrap should have a perm rating of at least 5 to enable walls to dry out in a reasonable period of time should they get wet.