Weatherization Tips from the Ground Up: The Basement

This time of year, most Mainers aren’t thinking about the dead of winter — unless, of course, it’s one of those rare sweltering summer days when cooler weather sounds like a dream. But believe it or not, summer is actually one of the best times to start thinking about winter comfort and home energy savings.

That’s because some of the areas in your home that may be a cool retreat right now — like the basement — can become major sources of heat loss once the temperature drops. Tackling weatherization projects before fall arrives gives you a head start on improving comfort and cutting heating costs when you can maximize your energy savings.

This blog kicks off a short series focused on home weatherization tips. Today, we’re exploring basement weatherization.

Why weatherize your basement?
A cool basement can be a blessing in the summer, but in the colder months, it can be a big drain on home heating. Insulating your basement walls helps maintain more stable indoor temperatures year-round — keeping them cool in the summer and warm in the winter.

We suggest insulating basement walls from two feet below grade up to the underside of the first floor. Consider using at least two inches of rigid foam board or closed-cell spray foam for this job.

For crawl spaces and basement ceilings, you’ll want to consider dense-pack insulation or a minimum of two inches of rigid foam or spray foam to help reduce air movement and retain heat. If you work with a Residential Registered Vendor you could qualify for available insulation rebates.

Don’t overlook the rim joist.
One often missed but important detail in basement weatherization is sealing the rim joist (also called the band joist). This is the seam where your home’s exterior framing meets the foundation. Sealing this area from the foundation up to the first floor can make a big difference in helping you prevent heat loss and reduce drafts and frozen pipes. When insulating, be sure insulation is between your pipes and external framing, so plumbing is isolated from the cold. That way they are much less susceptible to freezing.

Mind the gaps.
Particularly in older homes, gaps or cracks may exist where chimneys pass through floors and ceilings. These openings can create pathways for warm air to escape and cold air to creep in.
Likewise, pay special attention to areas where plumbing or electrical lines pass through walls or floors. Think of water or electrical lines that branch from a boiler or electrical panel, for example. These penetrations, as they’re known, can be another source of troublesome gaps.

Wherever you find gaps between heated and unheated spaces, sealing them is a great defense against heat loss. However, for gaps around chimneys and the like, be sure the proper fire-rated solutions are used, like fire-rated caulk and metal flashing. This particular solution is best left to professionals. As we mentioned earlier, you can find an experienced Residential Registered Vendor to help you make the most of your weatherization project.

Small changes can make a big impact.
Weatherizing your basement or crawl space may not be the most visible home improvement project, but it can have a big impact on your comfort and heating costs. A few targeted upgrades now can go a long way in keeping your home warm, efficient, and ready for whatever winter brings.

For more energy efficiency tips, review our tips booklet on our website here. To order a free printed copy of the Efficiency Maine Energy Efficiency Tips Booklet, email info@efficiencymaine.com, call 866-376-2463, or select it from our online order form here.