Air Sealing, Weatherstripping, and Draft Proofing

Air sealing is one of the fastest and most cost effective ways to conserve energy and save on your heating bills.

The average 20 year old home has leaks that would add up to a round hole 16 inches across. Left unsealed, these leaks are like leaving a small window open all year round, making the home drafty and more expensive to heat.

If your home is too leaky, basic steps such as weather-stripping, caulking and applying gaskets and tapes in your home can make your home far more comfortable and result in significant savings. 

Finding Air Leaks

Consider hiring a Certified Energy Advisor to conduct a depressurizing fan (aka 'Blower Door') test. The Advisor will place a powerful fan in an outside doorway. After closing all windows and openings in the home the fan is turned on. As the fan runs, the house becomes depressurized. You and the Advisor are then able to walk around the house feeling for problem areas where air is leaking through. The test also determines the house's total leakage area, and the air exchange rate per hour. You can also have your home tested to see if it is too tight and may be at risk of combustion spillage, where exhaust systems pull dangerous combustion gasses, including carbon monoxide, into the home.

Air Sealing Tips

Caulking is used to seal leaks in walls, ceilings, and floors. Caulking should only be used on the inside of exterior surfaces to prevent air from escaping and also to avoid exposure to outside elements.

What you will need: tubes of caulking and a caulking gun.

TIP: There are many different types of caulking. Make sure to choose the right kind! Inexpensive or inappropriate caulking can lack durability and be hard to apply. Look for a “Low VOC” or “No VOC” brand to ensure you are buying products that will not off gas (or off gas less than conventional brands). VOC = Volatile Organic Compounds.

Weatherstripping should fit tightly around all doors and windows. For exterior doors use weatherstripping around the sides and top of the door (jambs) to reduce air leakage. Replace worn stripping. For single-hung windows, use a V-Strip and compression-type weatherstripping. Depending on the type of window you have there will be different types of weatherstripping.

Electrical outlets can be sealed with special foam pads approved by CSA International along with safety plugs in rarely used outlets.

TIP: When installing new outlets use an electrical box air barrier to stop air and vapour leakage.

Trim Areas Use caulking to seal all baseboards, mouldings and window and door casings. For a more effective seal remove the trim and seal behind it, using a foam backing rod for large gaps and then seal with caulking.

Attic Hatches can be sealed with caulking around their frames. Apply weatherstripping along the casing and make sure the hatch fits snugly between it to create a tight seal.

Fireplaces should be left with dampers closed when not in use to reduce air flow throught eh chimney. Don’t use your fire place? Consider installing a removable plywood cover or a Chimney Balloon to stop air leakage.

More Air Leakage Tips