The property was built in 1908. The basement walls are concrete & stone, about a foot thick. The basement walls are newly parged and they used a wire mesh under the parging. The basement has a gravel floor. Main floor is hard to heat because it is right over unheated basement. Heating costs are high. If I was to insulate the walls, would it keep the lower floor warmer? Would it save on heating costs? Should I use rigid foam or pink insulation?
Answer:
You're on the right track, the walls are what you'll want to insulate but you should also spread an old swimming pool liner on the floor because it is bleeding moisture up throughout the year and you're paying to heat that moisture as it goes on up along with mildew odours it leaves behind.