Weather Barrier #DoneRight

March 7, 2016

Weather Barriers done right means weather barriers that go to work on more than just sunny days

Weather includes moisture, wind, and rain, so it makes sense that a Weather Barrier would aim to stop all of that. 

Because it is not always sunny like it is in animation land. The details in this animation come from BOWA, a Design, Build, Remodel, and Consultation company in McLean and Middleburg, Virginia. A video presentation explaining this more in-depth is here: How To Install House Wrap #TheRightWay

 

Step by step:

  • Begin at the bottom of the wall where the house wrap is sealed to the foundation with high-quality silicone or polyurethane caulk, to bridge the gaps between wood and concrete.
  • Anyone who has ever run siding knows that if the house wrap isn’t tight at inside corners, it will get sliced with a utility knife, so either get it tight or say goodbye to your air barrier.
  • Overlap vertical seams 6 to 12 inches. Here, the house wrap is run all the way into the corner and the next piece run out about a foot and a half because there are a couple of wall elevations at the bottom and the installers wanted to get a good overlap.
  • Tape the seam with contractor tape
  • Run a bead of caulk along the top of the wall to seal the house wrap. Sometimes its easier to do this after the house wrap has been placed. Either way, overlap the higher pieces in front of the lower pieces so that water is always directed out of the walls.
  • And don’t stop at the top of the insulated space — House wrap is the drainage plane on gables too, so it has to cover all wall sheathing. 
  • It's a good idea to tape the seams before going crazy with the cap stapler because a partially taped-over cap staple can become a water injection system into the tape, which can become a trough for sideways water movement. So keep the cap staples away from the tape. The same is true at windows, where there is a lot of flashing tape.
  • Keep the cap staples away from the window opening about a foot on each edge to allow plenty of room to splice the window into the wall.

Another sneaky spot that can turn into a massive air leak is a cantilever. At a minimum, cover this opening with house wrap, but something rigid is better, like sheathing. Of course, using both sheathing and house wrap are best and that detail is a topic for another video.

 

—Doug Horgan is a Vice President of BOWA, a Design, Build, Remodel, and Consultation company with offices in McLean and Middleburg, Virginia. 

 


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