Sealing attic bypasses is the #1 home improvement that every single homeowner in Minnesota and South Dakota should do. Air leaking only comes into your home because it has a space to do so, and usually that space is your attic. Attic air leaks also contribute to damaging insulation and other building components. Water vapor carried with the escaping warm air may condense, freeze and build up in the insulation. When this water builds up it can soak the insulation, and wet insulation has almost no insulating value.
Hot air leaking from your attic can cause many more problems than just losing the heat in your home. It can cause Ice Dams to form on your roof. These are caused when the snow on your roof melts. You will see icicles forming on your gutters and eaves, right where the water refreezes. When this happens, it can force water back up under your roof shingles, through your sheathing and into the house. The most effective way to prevent ice dams and the costly damage that come with them is to seal your attic bypasses.
A quick way to see if you need more insulation is to look across your uncovered attic floor. If your insulation is level with or below the attic floor joists, you probably need to add more insulation. The recommended insulation level for most attics is R-38 (or about 12-15 inches, depending on the insulation type). In the coldest climates, insulating up to R-49 is recommended.
