Canadian winter is a force to be reckoned with. That means keeping the cold air out (air infiltration or leakage) through tight sealing of the enclosure. It also involves reducing coldness from the ground (conductive heat loss to the cold earth) which can make the basement living environment very uncomfortable. 

In this video, Building Knowledge Canada Vice President Andrew Oding explains the advantages of under-slab insulation—and it’s not just about temperature. 

First, under-slab insulation warms the concrete. You can tell when you step on a slab with your bare feet whether it's insulated. “In fact, we've had floors that have been insulated without in-floor warming, and the homeowner thinks there are warming pipes in the slab”, states Andy. When we warm the slab with the insulation, all of the hardwood, carpet, or flooring you're putting in the basement remains dryer. This is due to the insulation raising the surface temperature above the dew point of the air. This also reduces the traditional musty basement smell.

Secondly, air leakage brings a lot of cold moist air into the basement. Some insulation applications can serve as good air barriers, keeping the cold air, water vapour, and soil gases out of the basement, making a home healthy and comfortable.

Third, some insulation products can serve as a good vapour-control layer. This control layer limits the amount of vapour diffusion into the basement space. It’s good to remember that it is always 100% relative humidity and that water vapour wants to move into the basement. 

Fourth, some insulation materials are certified or qualified radon barriers. These materials have been third-party tested, validating their ability to reduce radon ingress through air leakage and diffusion. This is something every family in Canada should be concerned about.

So, just as winter temperatures should be a consideration in insulation choices, soil types, moisture, and even radon readings should be examined. Consult our Builder 360° program to find out more about how the expert team at Building Knowledge Canada can help you to build better.

Connect with us anytime, and let us know what outstanding questions you might have on this subject.