Matt Risinger
Delta-Vent SA peel-and-stick membrane air-seals walls as well as protecting them from moisture. It should be used with a rainscreen.
I’ve been very impressed with a German peel-and-stick product, Delta-Vent SA that we recently used on a house. There is a fair amount of labor involved in the installation: The sheathing is first covered with a paint-on primer. Then the 3-foot-wide material is unrolled on the wall; once it’s in position, you pull off the backing paper and smooth it into place. A double-stick layer at the edges creates an airtight seal at all the overlapping seams. There are also proprietary tapes for flashing windows and wall openings.
Another peel-and-stick product we’ve used is Aluma Flash—a laminated rubberized-asphalt product. The rubberized-asphalt layer is 40 mils thick and laminated to two layers of polyethylene film, with a top protective layer of aluminum. The aluminum outer layer helps this product withstand UV rays almost indefinitely. It’s applied similarly to Delta-Vent SA.
Matt Risinger
Its aluminum outer layer helps peel-and-stick Aluma Flash withstand UV rays almost indefinitely.
We have also used fluid-applied flashing and seam-sealing products from Tyvek. They work extremely well for tricky inset window installations. You squirt them on from a caulking gun, then use a trowel or brush to spread the materials, which have the consistency of thick paint. Once cured, they form a rubbery, airtight and watertight bond.
We have not yet used any fluid-applied products to completely cover the walls of a house, but some of the products that look promising are Tremco’s ExoAir 230, Tyvek Fluid Applied WB, and Grace’s Perm-A-Barrier Liquid.
Fluid-applied weather barriers are elastomeric products that can be sprayed, rolled, and even brushed on a wall. Depending on the product, some joint and seam filling or priming may be needed first. The cured products form an elastic, airtight, vapor-permeable, and waterproof covering that will stretch and contract a bit as a building moves.
Residential-grade fluid-applied products are thinner, however, than commercial-grade products, which range in thickness from 30 to 75 mils. At that thickness, the material is almost squishy when cured and provides something of a gasketing effect around fasteners for brick ties and the like. My current preference at this point would be to specify one of the commercial products.
This article originally appeared in JLC, BUILDER’s sister publication.
