I’m renovating a basement in Sherbrooke, Quebec, where we don’t insulate the bottom 15 to 18 inches of the foundation so as to avoid freezing down to the footing. There is no styrofoam on the outside – that would require bringing in a shovel etc – added cost.
This basement has an ajoining concrete cold room (about 5 ft. wide) built along the entire length of the front wall, thus creating a double foundation. The roof of the cold room is the concrete floor of the front balcony. If I insulate the front wall of the basement to R 10 down to the usual 18 inches, I’m afraid the heat loss into the coldroom could be insufficient and frost could reach down to the outside cold room wall footing causing major damage to the foudation.
My question is, how do I figure out how much insulation to use on the front of the basement and should I insulate the outside wall and ceiling of the cold room and how much?