Frost heave / Discussions

What are the best below grade drainage layers for a slab on grade foundation?

...frost heave, and given that frost forms on a 45 degree angle from the surface, that skirt can have as little as a 2% slope all the way up to being completely vertical. All that matters is that it slopes away from the house so that any standing water drains away from the slab and not towards it.

Posted by stephan prystanski April 7, 2025 Slab on Grade 1 response

Can you leave a Legalett slab in winter in Canada without the heat on?

...frost heave, as is often the case with detached garages. As for the heat source (air or hydronic), that has no impact on frost heave, nor is there any impact between the 2 and 4 inch pipes. You can read here to compare air heated radiant floors to hydronic, we’ve done both and much prefer air heated, you can see our ti...

Posted by Gamog Cladhaire April 29, 2021 Slab on Grade 3 responses

Have you excavated under one of your slabs middle of winter?

...frost heave  -  All About Frost Heave Prevention in Cold Climates Our last slab was built on a Legalett frost protected slab on grade, and Legalett has installed them all across North America and into the far north and after decades in business they have never had a single structural failure. And if you are asking for ...

Posted by Mike Kolder Jan. 31, 2021 Slab on Grade 1 response