What does house wrap do?

Q:

What does house wrap do?

A:

The housewrap, or weather-resistant barrier (WRB), is applied to the wall sheathing before the doors, windows, and siding are installed. It acts as a secondary watershed if any water gets behind the siding, while also keeping unwanted drafts out of the home.

But while it’s impermeable to air and liquid water, it’s permeable enough to let water vapor from inside the structure escape to the outside. This keeps moisture from building up in living spaces and wall cavities, where it might condense and encourage mold or mildew. There is at least one sheathing product with a built-in protective overlay that eliminates the need for a separate housewrap.

When using a conventional housewrap it is important that the installers pay particular attention that the housewrap has every joint properly tapped with tuck tape. Tuck tape is an engineered tape that is designed for housewrap applications. This ensures that the housewrap is consistent all the way across the wall. All cuts, rips or joints in the housewrap must have this tape applied to the seams to guarantee the product works at its maximum potential.

It also should be noted that the house wrap (when it is being installed) should be stretched tight and be stapled with a smooth finish. This helps later when siding is being installed and the strapping does not have to ride over folded housewrap making an uneven surface.

There are new warranty concerns if you only install housewrap with conventional staples, to be fully covered by the manufactures warranty it must be installed with staples that have 1" plastic washers attached to them. This helps minimize ripping in the housewrap around the staples and maximizes the holding potential of the staples in high winds.

Rob Abbott
Village Builders Inc.