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Air Sealing

There are a couple of approaches you can take to air seal (or draft proof) your home.

Hire a professional

If you know your home is drafty and you want to be thorough in finding and sealing leaks, you should call in a professional.

A professional contractor will identify sources of leaks and drafts in your home and then thoroughly seal them. This approach will ensure proper air sealing of your whole home.

Proper air sealing can result in cutting your energy use by as much as 20 – 40%.

Air sealing should happen before any other projects, like adding insulation or upgrading your heating system upgrades. If you’re re-wiring your home or renovating, this is the ideal time to seal any and all leaks.

Do It Yourself

If you’re air sealing your home yourself, here’s what you need to know to get started.

Get Ready

  • Get ready by removing old or damaged caulking and weather stripping before you begin.
  • Pick up the proper materials such as the right type of caulking for the job, foam backer rod for use behind caulking in large gaps and weather-stripping that you’ll need for your air sealing project.

Find leaks

  • Find leaks by holding your hand or a feather next to windowsills, doors and joints at walls and ceiling or floors on a windy or cold day to check for drafts. Start in the basement and work your way up the main levels.
  • Note: On windy days, you’ll only feel air leakage on the side of your house that the wind is blowing on. You can also turn on all of the exhaust equipment in your house to create a negative pressure similar to what professionals do with a blower door to find air leaks. Exhaust equipment includes bath and kitchen fans, your dryer and the central vacuum system.
  • Air leaks happen where there is a hole in the building envelope and a pressure difference. When cold air is leaking in to your house, you can be sure that just as much warm air is also leaking out somewhere else.
  • Your home can shift over time (with moisture and temperature changes) which can open up gaps and cracks. Use caulking or other expandable materials to seal between interior joints, around non-opening windows and spaces around water pipes and vents.
  • Don’t forget to check your attic hatch, ceiling penetrations into the attic, doors, exhaust vents, mail slots, basement sills and headers, electrical service entry, floor drains, foundation cracks, electrical outlets, windows and your chimney for cracks.

Sealing Doors and Windows

  • Doors can warp over time leaving gaps between the door and frame. If your exterior doors are drafty, add or repair the weather stripping along the top and sides of the door. Exterior doors and windows should close tightly, as should interior doors to unheated areas.
  • Install a door sweep on the bottom edge of your door, or attach weather stripping along the bottom of the door or on the threshold. Use weather stripping and caulking to seal around windows and window trim.
  • Cover single-paned or inefficient windows with plastic or fitted storm windows in the winter.
  • Keep doors and windows closed when operating heating or air conditioning systems.

Use weather stripping and caulking to seal around windows and window trim.