re: Insulation for Raised Houses

Unfortunately, this is a pick your poison type thing, but batt insulation under a house is useless. Pull that shite out.

Then you’re left with an all or nothing choice. Nothing gets you real discomfort in a week like this past one, but the bigger issue in our climate is moisture intrusion in the warmer months. The warm, moist air under the house is seeking equilibrium and pushing up through your subfloor to meet that cool, conditioned air. That creates condensation issues that can potentially buckle your finished flooring and even rot the subfloor.

The LSU paper referenced is good info. The closed cell foam or polystyrene options have some great selling points, but— again— also some trade off. You can wipe your arse with a termite contract in my experience, so other than masking possible termite activity, forget that part of it.

I did closed cell under my house years ago and had a water line fail. It was a huge mess because the water has nowhere to go. That said, I put it in because I had crazy drafts in the house and buckling floors. So, once I replaced everything, I went with the foam again and I hope I don’t get a repeat. It’s a gamble. Good luck.