I got a quote of $9000 to dig down and insulate an exterior basement wall, which is under a deck with only a 3' clearance. I'm wondering if I could just lay rigid insulation on top of the ground outside instead. Would that work to improve the insulation value of the ground and help with the cold Canadian winters? Also, how can I protect the insulation from pests?
2 Answers
Lol, that approach is definitely not going to work! You really need to address the insulation from the ground up rather than just adding something on top. That being said, for pest protection, consider using barriers like hardware cloth or special pest-resistant insulation boards.
Unfortunately, just laying insulation on the ground isn't going to cut it. Insulation is meant to slow heat transfer, and if the ground is already cold or frozen, that approach won’t really help. It’s like trying to keep your hand warm by wrapping a towel around an ice bucket – it just won’t work. You'll need real barriers to actually combat that cold air reaching your basement.