How to Find and Fix Air Leaks and Drafts in Your House
As winter approaches, it’s a good time to think about whether your home is well sealed or too drafty. Does your heating or cooling system seem to cycle off and on too frequently? If so, your home may be leaking too much air.
Air leaks and drafts that let heat escape in the winter (and allow hot air in during the summer) often aren't easily detected because they are usually the result of problems behind walls or in other hard-to-reach places.
Common Areas of Household Air Leaks
Locating Air Leaks
One way you can check for air leaks on your own is to purchase a thermal detector which is made specifically for finding air leaks in your house. The most effective way to check the tightness of your home is to get a professional home energy evaluation. This should include a negative air pressure test, also called a blower-door (depressurization) test, as well as thermal imaging. These tests will reveal hard-to-detect areas of air infiltration and missing insulation. The U.S. Department of Energy also offers helpful advice on detecting air leaks.
Fixing Air Leaks and Drafty Areas
Basement: Caulk is best for sealing gaps or cracks that are 1/4 inch or less. Use spray foam to fill gaps from 1/4 inch to 3 inches. Also, seal penetrations that go through the basement ceiling to the floor above (usually this will be penetrations for wires, water supply pipes, and venting)
Attic: No matter what kind of insulation you currently have in your attic, one quick way to determine if you need more insulation is to look across the span of your attic. If your insulation is just level with or below your floor joists, you should add more. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches.
A great resource with additional information on insulating and fixing air leaks is provided in a publication from Energy Star.
Editor’s note: This post was originally published on December 13, 2011 and has been updated to provide new information.