Is your basement cold in the winter and uncomfortably warm in the summer? If so, you could have an insulation issue that’s costing you money when it comes to heating and cooling your home.Basement insulation is often overlooked, but once you know the symptoms, an insulation problem is easy to spot.
If you do discover that your cellar needs a better buffer against the outside, the following strategies should help you to seal, insulate, and protect your basement space.
Photo: Home Depot
Basement Insulation: Symptoms of a Problem
You can check for basement insulation problems at any time of the year. Here are some conditions to look out for:
Whether it’s winter or summertime, a poorly insulated basement lets in moisture and condensation, and these elements foster the growth of mold. If you find collected water, or you find a colony of mold itself, then it’s probably time to insulate.
2. Cold Walls:
If they’re chilly to the touch, it’s time to hit the hardware store for supplies.
3. Heating/Cooling Costs:
Another early warning of basement-insulation issues can be found in your heating and cooling bills. If your home isn’t generally drafty — that is, if your upstairs levels stay comfortable throughout the seasons but your expenses don’t match — the basement is probably where you want to look to find the problem.
There are two basic ways to insulate your basement: from the inside or from the outside. Here’s a breakdown on how both can work:
Interior Insulation is probably one of the most common methods of sealing a basement against heat loss and summertime heat intrusion. Insulation from the inside means placing a moisture barrier along the height and width of all foundation walls. The next step is to frame inwards from each wall and fill the frame with fiberglass or cellulose. An air barrier is left between the warm side of the insulation and the wall-face (this makes the insulation process a fine time to think about generally remodeling your basement). Make certain that you’ve dealt with any interior basement-moisture problems beforehand.
Exterior Insulation is a method often employed in connection with passive houses — residences built with low energy-use in mind. This method requires that you excavate around the outside of the foundation, install a dampness barrier around it, and then apply rigid-style insulation such as foam panels before closing up the dig. This is a particularly effective way of insulating brick and rubble foundations. It’s labor intensive, but you won’t lose any square-footage behind newly framed walls on the inside of your home. (For a more comprehensive look at all the issues surrounding basement insulation and passive houses, check out this FAQ from the Canadian Passive House Institute.)
Some Notes on Insulation:
Be certain that you check with your local municipal authorities before you start adding walls or excavating. Building codes are particular things, and you don’t want to discover that you’re liable for a fee or fine after you’ve already begun.
Also, note that different kinds of insulation material offer different levels of protection from the heat and cold. This is typically measured as a resistance-value or R-value. For a table of the types of insulation sold in Canada and their relative R-values, check this page at the Canada Mortgage and Housing Corporation.
By James O’Brien