Air sealing is the single most important thing you can do to make your home efficient, comfortable and healthy.

Leaky homes, like leaky boats, are a source of trouble. They’re uncomfortable, inefficient and unhealthy.  If your goal is to have a comfortable, energy efficient home, finding and sealing air leaks is the most important thing you can do.

Why? Air leakage is the source of three kinds of grief for homeowners:

  • High heating bills. Air leakage wastes energy. A drafty home can drive your energy costs by stealing your hard-earned heat and creating more work for your heating and ventilation systems.
  • Uncomfortable drafts. You can blame air leakage for chilly drafts, cold floors and cold spots in your home.
  • Moisture problems. Air leakage can contribute to moisture problems by allowing moisture to seep into your home, causing mold, mildew and poor air quality.

The good news is that most air leaks can be fixed, some by you and all by a professional.

Air sealing is the process of plugging any leaks in your home that allow cold air to enter and warm air escape. (In the summer, the reverse happens.) It’s one of the most cost-effective ways to keep your home cozy in winter. Also, it’s the most important first step in creating a more efficient home.

Air sealing is done with caulking and weatherstripping, gaskets and tape. The approach depends on the location, size and nature of the air leak.

Since heating can account for up to 60% of your home energy bill, air sealing can make a big difference in heating bills. Draft-proofing your home and insulating well can reduce your heating bill by as much as 10 %.

There’s nothing like a Canadian winter to make you aware of air leaks in your home. Feeling drafts around doors and windows, and chilly floors, can be upsetting and just plain uncomfortable. Cold air is insidious and will make its way into your home in all manner of ways.

The most common sources of air leaks in your home:

  • Around doors, including the threshold and around the door frame.
  • Around windows, frames and sashes.
  • Around plumbing pipes and ductwork, exhaust fans and vents.
  • Cracks in walls and ceilings.
  • Light fixtures in the ceiling.
  • Electrical outlets and switches, on interior and exterior walls.
  • Chimney and fireplace (doors and damper).
  • Interior trim and baseboards.
  • In the basement: Sill and header, electrical service entry, floor drain and foundation cracks.
  • Other: Doors and hatches into unheated attics.

The most thorough way to air seal your home is to hire a professional. Some leaks are more difficult to identify and to seal. A professional knows exactly where to look and has equipment to help identify and repair air leaks.

However, you can do some leak fixing on your own.  

  • Caulk around window and door trim. Caulk the top and bottom of your baseboards and quarter rounds and not just those on exterior walls. No crack is too small to be sealed.
  • Check weather stripping around windows and doors and replace any that isn’t doing its job/that’s worn. Use a feather to see if drafts are coming in (or heat is going out).
  • Insulate your light switches and outlets with special foam gaskets designed to fit neatly behind your light switch and outlet cover plates. Put child-safety plugs in empty wall sockets. (Both are available at most hardware stores)

Energy savings and a more comfortable home aren’t the only benefits of air sealing. Sealing leaks helps to control moisture in your home so you don’t have problems with mould and mildew. It also keeps outdoor pollutants from seeping in.

While a tight home is the ultimate for efficiency and comfort, it’s important to understand that a well sealed home needs to be supported by a ventilation system to control the flow of fresh air in your home, for climate control and air quality.

If you want to make your home energy efficient, start with air sealing. It’s the single most important thing you can do to make your home comfortable, healthy and efficient.

FAQs

How to seal air leaks:

Air sealing is done with caulking and weatherstripping, gaskets and tape. The approach depends on the location, size and nature of the air leak. Caulking is used to prevent air leakage around windows by sealing gaps around the window trim with a continuous bead of caulking. (There is indoor and outdoor caulking. Be sure to use the correct type for your project.) Outdoor caulking should only be done after indoor sealing is complete.

Weather-stripping works best for doors that are used often, and windows that open. It provides a good seal against air leaks even as doors warp from season to season.

How much of a difference does air sealing make?

Since heating can account for up to 60% of your home energy bill, air sealing can make a big difference in heating bills. Draft-proofing your home and insulating well can reduce your heating bill by as much as 10 %.