SEAL THE AIR LEAKS

ISSUE: You found a bunch of air leaks.

SOLUTION: Most leaks can be fixed with a caulking gun and a can of spray foam. For wider gaps, use backer rod (soft, round foam strips that help the caulk bridge the gap). Caulk on the indoor side of a house lasts much longer than caulk on the outdoor side, because outdoor caulk is exposed to ultraviolet light from the sun, to rain, and to the stretching and shrinking of adjacent materials caused by changes in outdoor temperature. Leaks in a foundation can be closed most of the way with cement if they are large enough, then closed up the rest of the way with silicone caulk. Air leaks around a window can be sealed with caulk if they are no larger than about 8 mm, or with foam and then caulk if they are larger. For electrical outlets, caulk around the box, or, even better, buy cover plates with gaskets. Air leaks around doors require weather-stripping products. Look for the ones that work by compressing a seal. Those that depend on one surface rubbing against the other will not last long. The most difficult part is the bottom of the door. Installing a saddle under the door gives any weather stripping along the bottom of the door something to close against. Other products can actually lower themselves down from the door automatically when the door touches the frame.