I bought a log home with 8″ T&G log walls that are D shaped so they are flat on the inside. In some of the rooms the original owners either painted or drywall over the inside surface of the logs. I like the log look and am going to put up T&G pine to cover the paint or ugly screw holes.
My question: is it a good idea to cover the entire inside surface of the logs with 1/2″ polystyrene rigid foam then put the pine over that? I live in the Adirindacks of NE New York and it is very cold here (-3 right now). I just want to make sure that the foam would not be putting a vapor retarder on the wrong side and lead to moisture problems.
Thanks for any input.
Replies
I think you'd be OK. In that climate you want to keep moisture in.
Putting the rigid on the inside is fine. It also would put the VB on the inside ... where it should be. You'll have to deal w/ electrical and/or plumbing, but that's doable. I'd put more than 1/2" on it though. If you are going to do it ... add the R-value that would normally be required.
In case you or someone tends to bring up the thermal mass argument ... forget it. Thermal mass is not particularly beneficial (it CAN be, but only under certain circumstances which at your location, doesn't likely exist). I'd have a tendency to install e.g. a solid 2" of polyiso (R15+) in your situation. 1/2" of poly might only give you about R-2.2 or something like that. If you are going through the trouble, this is your chance to bump it up a notch and do a good job (thermally).
Thanks for the reply. I actually decided to go with 1 inch blue rigid foam. In the rooms where the logs look good, I am going to leave it alone. We really don't have to much trouble keeping the house warm with woodstove and gas forced air. I just thought, if I am going to cover the walls anyway, I might as well bump it up a notch.
There is no plumbing in any of the exterior walls and the electrical comes up through the floor into boxes that bump out of the base boards.