Seal Air Leaks

Download this information in Adobe PDF format.

You can save 10% or more on your energy bill and make your home more comfortable by fixing the air leaks in your home.  Eliminating all the gaps, cracks, and holes that let air into your home is a simple and effective way to cut energy waste and make your home more comfortable.

Where To Look For Leaks

• Exterior windows and doors. Check the door to the garage as well.
• Interior attic and crawl space access covers.
• Plumbing penetrations under sinks.
• Recessed lighting.
• Clothes washer connection panels and electrical panels.
• Attic joists from side attics. Air flows under the upstairs floor from the side attic.
• Through faulty kitchen and exhaust fans.
• Up and around chimneys.

Once you’ve spotted the leaks, the next step is to choose the right project to seal them. If you aren’t sure what to use, talk with the staff at your local hardware or home improvement store.

How To Find Leaks

On a windy day, hold a lit incense stick next to your windows, doors, electrical boxes, plumbing fixtures, electrical outlets, ceiling fixtures, attic hatches, and other locations where there is a possible air path to the outside. If the incense stick glows brighter or the smoke stream travels horizontally, you have located an air leak that may need sealing.

Sealing In Savings

The materials required to seal most air leaks are inexpensive and available at your local hardware or home improvement store.

Weatherstripping blocks air leaks around doors and windows that open. It comes in rolls or strips with adhesive backing. Choose weatherstripping that will fill the space without interfering with the operation of the door or window.

Caulking or sealant can be used to stop leaks around the frames of doors, windows, and baseboards, and to seal around plumbing or electrical penetrations.

Gaskets can be used to reduce air leaks in electrical outlets. Gaskets fit behind the cover plate and are most effective when the edges are caulked or sealed.

Door sweeps stop drafts on the bottom edges of exterior doors.

Tips for Do-It-Yourself Air Sealing

Sealing air leaks is a fairly simple and effective project that can cut energy waste and stop uncomfortable drafts.  Here are a few tips to help you get the most our of your air sealing project.

• Block the Path: Since air travels in the home through leaks in the floor and through leaks in the ceiling, sealing all the leaks in either the ceiling or floor will block airflow and dramatically reduce leakage.
• Fix Drafty Windows: Old, single pane, aluminum framed, or faulty windows can cause uncomfortable drafts and waste a lot of energy. The best fix is to replace them with new, ENERGY STAR® rated windows. If replacement is not an option, plastic window kits are a cheap and temporary solution during the coldest time of year.
• Seal Up Attic and Crawl Space Openings: Leaky attic and crawl space openings are a real energy waster. It is best to insulate the cover, weatherstrip the opening, and attach a latching system to hold it tight. To insulate and weather-strip pull-down attic stairs, build a box with a cover out of rigid foam-board insulation that sits over the access opening in the attic.
• Your Chimney Is a Big Hole: A chimney is a hole in your home designed specifically for smoke to escape. Unless you keep it closed, warm air escapes 24 hours a day! Keep the flue damper tightly closed when your chimney is not in use. (Wait a couple of hours after the fire dies.) If you don’t use the fireplace at all, consider a chimney balloon. Dampers reduce leakage but don’t seal it off as well.