Little or No Air Sealing
When inspecting a home, Gordon starts by checking the air sealing. He’s often disappointed by what he finds: Not enough sealant at the tops of windows, fiberglass insulation used as an air sealant, or no seal around important areas such as doors, bandjoists, top and bottom plates, and ceiling penetrations. Armstrong frequently finds that foam gaskets are pulled off by drywall installers. “I’ll see a big pile of it in the middle of the floor,” he says.
Consequently, inspectors and verifiers spend a lot of time talking with builders and their partners about air barriers and avoiding thermal bypass, which allows cool or hot air to slip in to a home’s conditioned space and practically negate the value of insulation. “Having proper air sealing is critical for performance,” Armstrong says.
Tough new energy codes will soon force builders in many states to pay more attention. The 2012 International Energy Conservation Code (IECC) requires blower-door testing and a visual inspection to ensure that a home is as airtight as possible. To help builders facing new codes, Dave Wolf, senior research and development project leader at Owens Corning Science and Technology, set out to prioritize the leaks in a house by ranking which ones have the biggest impact on air infiltration. Acknowledging that many builders have a limited budget for air-sealing, his goal was to identify the leaks that would give a builder the most “bang for his air-sealing buck.”
In addition, Home
Innovation Research Labs have analyzed several techniques that have proven
to provide efficient air sealing, most at little additional cost.
