Dry and durable walls come from keeping water out and giving it a way to get there
The WRB must protect walls in more than just the easy spots, like the middle of a solid wall. Door and window openings are key places to execute best-practice flashing details
At ProTradeCraft’s Demonstration House in the Show Village of the International Builders’ Show, we had a couple of Tyvek specialists flash a door and demonstrate how to install their new DrainVent product.
Tom began by flashing out simulated deck ledger using DuPont flashing tape.
When the Tyvek is installed, it is lapped over the flashing tape. If using Tyvek as part of the air barrier system, all of the seams and the bottom of the sheet would be taped, as Tom points out here.
The Tyvek is cut flush with the door, and flashing tape is used to seal the Tyvek to the framing.
At the base is a sill pan flashing, done with flexible flashing tape.
First, he gets the length right, and then he folds along the split release seam.
Sticking the top of one side onto the framing, he places the flashing, peels one side of the release sheet, and pushes the tape in place. Now, he pulls off the other half of the release paper and bends the tape around the corners.
With the walls safe from liquid water, we can provide a fast path out for anything leaking past the siding.
Part 2: DrainVent
Snap a line 48 inches above the mudsill and place the DrainVent. DrainVent is a fibrous mesh attached to a filter fabric which allows water to drain down while keeping mortar from stucco or manufactured stone away from the WRB.
Tom Baiaida: "What that filter fabric does, is in the cases of stone and stucco, This will serve as an intervening layer. So typically, you'll install the house wrap first and then an intervening layer, that's typically a black paper; in this case, this will serve as that secondary layer.
And what that filter paper does is ensure that no mortar infiltrates through into the mesh to make sure you get the drainage and drying that you're after."
With the rainscreen on the wall, put a nail or staple in the top corner. Align the other end with the line and nail or staple off the top.
At the bottom, wrap the flap up to keep bugs out and nail or staple to the wall.
Tom: "What we try to do is minimize the number of fasteners. really, we just want to put this on the wall, understanding that the cladding will go on soon after. So we try to minimize additional holes ijn our weather barrier.
So what the installation guidelines call for is a fastener at the top, a fastener toward the bottom and a fastener in the center, every other stud. So I'm going to use the markings on the tyvek to gauge fastener spacing every other stud. So, 16 inches, 32 inches (tap, tap, tap).
For multiple courses, we're going to butt the two courses together and that flap will overlap."
For the second course, tuck the bottom flap outside the lower sheet, to keep bulk water flowing the correct direction, down and out.
Vertical seams can be butted directly together with no need for tap unless using stucco or stone veneer.
With these details, you’ll keep water moving down and away from your walls, and your demo hut will always be sitting in the sun.
—This video is part of a series of videos shot at the 2019 International Builders' Show in the Professional Builder Show Village onstage at ProTradeCraft's Demonstration House. See all of the videos here.