How to Insulate an Attic

Up to 45% of your home's energy can be lost through an inadequately insulated attic. Adding insulation is a very easy way to save money on your energy bill, make your home more comfortable, and add to your resale value.

According to the Department of Energy, most attics have between 3 and 6 inches of insulation, but they recommend up to 12 to keep those heating and air conditioning bills under control in most parts of the country.

If the top of your insulation is below the top of the joist, then you'll need to add more, laying it in the same direction to bring it up flush with the top. If you add more insulation, don't use the type with a paper vapor barrier; it can trap moisture between the layers. Instead use insulation wrapped in a breathable perforated poly sleeve.

Once the cavities between the joists are full, additional layers of insulation should be applied perpendicular to the joists.