A basement’s concrete slab must be well insulated.
We would also like to draw your attention to three features:
If you want to install heated floors in your basement, you are required by law to insulate the entire surface of the basement slab to an R-value of 10 (1.75 inches of sprayed polyurethane foam).
Overhanging floors are popular in Québec, and it is not uncommon for them to cause insulation deficiencies, such as cold areas above the overhangs. A specific insulation technique must be applied in order to avoid certain pitfalls and problems.
Floors above heated garages are required to be insulated to R-29.5. When a room is built above a garage, infiltration problems are very common. The result is a cold, unpleasant floor, and additional heating costs.