Leakproof Housewrap Patch
Housewrap often gets damaged in a couple of spots before the cladding is installed, and it has to be patched to perform its primary function: keeping water out of the building. Your first impulse may be to reach for a roll of tape. Don’t do it. When it comes to shedding water for the long haul, a mechanically lapped patch is always preferable to an adhesive one. The drawing shows a quick way to size and install a patch the right way.
Cut a rectangle of housewrap that’s roughly a foot wider and taller than the damaged spot. Fold a tapered hem on one edge about 1 in. wide at the top and tapering to nothing at the bottom corner. Center the piece so that the top edge is about an inch above the damaged area, and make a horizontal cut in the housewrap about 1⁄4 in. wider than the top of the patch. Slip the top of the patch into the cut, and raise it enough so that its edges nuzzle up to the ends of the cut. Staple the patch at each corner. Finish the patch by taping along the edges for a good air seal. Now any water that drains on the housewrap will lap over the patch, bridging the damaged area.
Mike Guertin, East Greenwich, RI