This is DuPont Tyvek Drain Wrap commonly know as “wrinkly” Tyvek. In previous installations, we’ve used regular smooth Tyvek and battens to create the drainage plane behind the siding. This wrinkly product promises to create the drainage plane without the battens.
This post reports on what we encountered:
We wrapped Bituthene around the framing before the windows were installed. Some of the windows had nail fins, and some didn’t. The windows that didn’t got fabricated sheet-metal pans sloped to drain. Note the sheet metal is Rezi-Bond, galvanized metal coated to promote paint adhesion.
We foamed the gaps between the windows and the studs. Where the foam oozed out, we trimmed it off carefully with a serated kitchen knife. The Tyvek carried over the Bituthene, over the foam, and turned out at the window. Then the trim boards and corner boards were pre-caulked and nailed over the Tyvek.
It’s hard to get it to lay flat! Wrinkly means wrinkly and the installation looks amateurish; it fans out, won’t stay level, and won’t lay down nicely. All that said, it shouldn’t make any difference to how it performs.
We’re installing Hardie plank in the 8″ Colonial pattern. You can see the slight indentation that transforms regular Hardie siding into “Colonial” siding. We had to order it in smooth in lieu of wood-grained and it costs slightly more, but it’s worth it; when it’s painted, from fifty feet away, if you squint, it almost looks like the original wood siding.
To get the first course of siding to lay at the same angle as the succeeding courses, we use starter strips. These are cut from 4×8 sheets of cored poly-styrene that we get from the sign shop. The cores allow the drainage plane to drain, but keep the bugs out.