Winter’s Coming: Seal Those Air Leaks!

Up in Maine this may be the most beautiful time of the year. Warm weather, bright sun, and just a hint of a nip in the air. Perfect time to get some work done.

One of the biggest sources of energy waste in most homes is air leakage through small cracks and gaps in the building envelope. While small holes may seem insignificant, they add up: it’s not uncommon for the total surface area of these air leaks to add up to the equivalent of leaving a window open year-round.

The good news is, a lot of these air leaks are relatively easy to seal up. Just takes an afternoon and a little elbow grease. Here are some tips on getting this relatively easy and highly cost-effective home energy upgrade completed:

Start in the basement.

Most of the air leaks in your home occur in the basement (or crawlspace) and attic. Since leaks in the basement are typically easier to access, it’s a smart place to start any DIY air sealing. Look for plumbing and electrical penetrations and spray ‘em with foam. Consider sealing the rim joist (where the foundation wall meets the wood framing) with either spray foam or a combination of rigid foam (despite how tight it may look, wood expands and contracts and this area can get mighty leaky; and fiberglass batt insulation doesn’t serve as an air barrier, so don’t waste your time with it.)

Tackle the trim.

Trim work - particularly along outside walls - are a prime point of air infiltration. This is because, while drywall seams are carefully mudded and taped, rarely is the spot where drywall meets other building materials sealed. This is why baseboards should always be caulked along the wall and the floor -- it looks better, of course, but it also prevents air from leaking underneath the drywall. Seams between drywall and post-and-beam framing should also be sealed for this reason. 

Check your attic.

When you were a kid, your mother probably always told you to wear a hat when you go outside in winter because heat escapes your body through your head. The same is true of buildings: hot air rises, and that means the heated air inside your house rises. All too often, attics are not sealed, so that hot air simply escapes the building and is wasted. While it's pretty difficult to air seal your attic once it's been insulated, be absolutely sure to air seal your attic before it's insulated if you're considering an attic insulation upgrade. And even if your attic has been insulated, depending on what type of insulation was used you may be able to do a little visual inspection and tackle the most obvious leaks (around chimney chaises, utility penetrations, recessed lights and attic hatches, in particular). 

Of course, a home energy audit is the best way to get a grasp of where your home is leaking energy, and a road-map to stopping it. Check out this post to read about how I learned 5 interesting things from an infrared scan during an energy audit, and check here to find a home energy auditor in your area.