Weatherproof Window Installation, Episode 3: Insulation and Air-Sealing
Working from the interior, Brian installs several layers of insulation and air-sealing
Insulation and Air-Sealing: Canned spray foam is probably the most common way of sealing between the window unit and the framing, but it’s worthwhile to go farther than foam alone, which can sometimes still allow air leakage. To eliminate air leakage and add some insulating value to the installation, use a combination of spray foam, flexible foam backer rod, caulk, and a layer of tape.
Read the related article:
A Weatherproof Window Installation