Framed basement walls are not flat against exterior walls: how to insulate?
The concrete foundation walls on my 100 year old house are not plumb. I recently had the basement framed to finish it. There's probably 6 inches at the top between the exterior wall and the framing at the top, and 3-4 inches at the bottom. I was planning on using fiberglass bat insulation. (This is not a house that I'm going to stay in for more than a few more years, but I do want to do it right if I'm going through the trouble.) Should I put in two layers of 3 1/2" bat insulation or buy some of the 6" fiberglass insulation? Or is there something else that I need to do?