How to find and fix drafts and air leaks

Many of you already know that Trish Long and I have recently become Registered Energy Advisors. We pursued this accreditation because energy advisors take a building science approach to analyzing a home. If you’ve ever had an audit done, you know that an advisor is able to both assess your home’s current energy consumption AND make upgrade recommendations. The recommendations usually fall into several categories including windows, walls, doors, new heating system, etc. however most often air sealing is at the top of the list.

Performaing an air leakage test using a blower door

An Energy Audit will provide you with a calculation of how much heat is lost in your home through leaks. A typical Toronto home loses approximately 30% - 40% of its heat through cracks. These small gaps may be around your plumbing intake, along your window trim,or even in your attic around your top floor potlights.

Air sealing is, for most homeowners, the low-hanging fruit that you can either tackle on your own or hire a professional firm like Goldfinch Energy.

Goldfinch recently air sealed three homes, each requiring a different approach. In all cases we used a blower door to simulate a 20+ km/h wind, which clearly identifies a home’s air leaks. With just a few hours of effort, we were able to significantly reduce air leakage and the homeowners were able to feel a noticeable difference in the reduction of uncomfortable drafts.

At the first home, air was leaking in between where the basement wall ends and the subfloor begins (this area is called a floor header). Spray foam was the best solution in this case because the basement is going to remain unfinished for now. Spray foam does the best job when it comes to air sealing cracks between 0.5” - 3”. You can purchase a can of it at your local hardware store. If you plan to do this yourself, be sure to read the instructions carefully, shake the can before use, wear PPE and don’t wipe up fallen drips but instead wait for them to dry.

At the second home, there were two gas fireplaces that had a noticable amount of air leakage around the edges. These leaks, although small in width but approximately 8’ in length, were sealed up with fire retardant clear caulk. As the fireplaces were focal points in the home, I made sure the caulking wasn’t noticable at all. We also sealed along the baseboards and addressed sources of air leakage in the unfinished basement.

Rockwool is an environmentally-friendly insulation choice for walls, attics and crawlspaces.

Windows are a common source of air leakage. If you don’t want to replace them, there are often ways to reduce the air leaks around them.

For the third home, half of the footprint of the main floor was over an unfinished crawl space, making the room above unnecessarily chilly. Trish and I spent a fun-filled morning crawling in and adding R14 worth of Rockwool between the framing and then covering this with professional spray foam (these kits are best for covering larger areas and should only be applied by a professional).

If you aren’t sure where your air leaks are, hire building science experts from Goldfinch Energy who can identify them using a blower door. For minimal cost, you’ll have noticeable improvements and we’ll share the measurable results from the blower door test with you. You’ll be well on your way to making your home more comfortable and energy efficient.