Last time we looked at the advantages of housewrap. Now we’ll show you how to install it.
Manufacturer’s instructions may vary a bit, so check them, but these basics should apply most of the time.
Install the housewrap before you install windows or doors in the openings.
Start at the bottom. In fact, one method is to lay a 2′-3′ strip of housewrap over the top of foundation wall, so that most of it lies on the outside, before installing joists. Then the housewrap can be wrapped up and over the wall. (It’s also a good idea to install an insulating gasket between the foundation and the sill plate.) Another method is to overlap the foundation wall by a few inches, caulking the housewrap to the foundation.
The rest of the work is definitely a two-person job. Hold the roll vertically, and starting a few feet from a corner (to make overlapping easier) start, well, wrapping. This layer should overlap the bottom layer by at least 6″. Unroll the paper, fastening it, ideally, to the studs with large-head, plastic capped or roofing nails. 1″ staples will also do the trick, but don’t have the same holding power. Roll the wrap right over window and door openings, keeping it as snug to the wall as possible.
Vertical seams should overlap by 6″ to 12″.
Install an extra layer of wrap in the corners (inside and out), since they’re more likely to get dinged and gouged as you work on them.
At windows, cut an X or an inverted, underlined Y in the wrap over the opening, and wrap the triangular sections inside the wall, sealing them there with tape. When you install windows with fins or flanges, cut a slit in the housewrap above the window, and insert the flange into the slit. Seal the joint tightly with tape. Tape the side fins over the wrap, but don’t tape the bottom flange, so that if any water gets in, it can easily exit.
Once the wrap is up, don’t wait too long to install your siding. Left exposed to the elements for more than a couple of months, it can lose some of it’s effectiveness.