I'm planning to renovate my basement, and could you please tell me the best way to insulate and frame the exterior walls. My walls are of stone and are not that smooth.
Answer:
When insulating any below-grade masonry wall it is best to build (in place) a 2X4 structure with studs 16" O.C. and pull it an inch and a half from the wall in order to accommodate R-20 fibre insulation bats without compressing them. The insulation actually goes from the sub-flooring above to within eight inches of the concrete floor and the 6mm polyethylene vapour barrier goes two inches lower so it can be pinched and stapled to each side of each stud. This keeps the insulation bats from sliding down and at the same time, the system avoids a lot of condensation problems. It also permits a bit of heat loss to the drainage tile along the exterior perimeter of the footings. In areas where frost is a problem, it is important that drainage at this point not be impeded.
