Though Sweenor Builders, the crew on the project, goes out of its way to build a tight house, all houses have air leaks. A blower door test on the Powers home showed 4 air changes per hour (ACH), considered to be tight. But a new air-sealing technology, first developed for HVAC ducts, reduced the house’s ACH to less than 1, all in about 60 minutes.
Here’s how it works: Lengths of tubing with spray-nozzle tips are set up inside the house on small tripods—several on each floor. Then, while a blower door pressurizes the house, a compressor pushes an acrylic-glue-like substance through the tubing and out the nozzles. The atomized gluey mist travels toward any air leaks, where it begins to collect around the holes. Glue particles stick to other glue particles, eventually clogging the opening. “This technology is a game changer,” says TOH plumbing and heating expert Richard Trethewey. “It’s a faster and better way to air seal any building, old or new.”
Shown: The post-and-beam barn arrived on-site in kit form. Cutting the barn frame at a factory, rather than on-site, saved time and money. After assembling the frame, the crew cut, then installed, the 2x12 rafters.