Basement Wall Insulation and Buildout
I'm in the planning stage for finishing off our basement. Right now, its just poured concrete walls and floors. Its an older house with this portion of the basement built in the 50's. The floor is in excellent shape and the walls are in good shape. There is some effloresence in a couple spots on the walls and the concrete is spalling a little here.
The effloresence is weird to me though. I live in northern MT (59522) and we are very dry with minimal rainfall (10" average annual rainfall). The majority of the wall are perfect, but there are 2 spots on opposite sides of the basement that have this problem and the concrete has spalled to about .3" deep (over probably 50 years). I also taped a 1'x1' clear plastic sheet to the wall in several location and have had them on there for about a year now. The worst I have ever seen moisture on the plastic was just a slight haze. Most the time it has been dry.
For the floors, I think we are simply going to acid stain them. Maybe skincoat, stamp, and then acid stain.
For the walls, I was going to build 2x4" stud walls around the basement. Use pressure treated sill plate with a sill plate gasket. I'll install the walls .5" out from the concrete and have a contractor come in and spray closed cell foam between the studs and the concrete walls, 2" deep between the studs, 2" thick over the concrete sill and wood foundation sill plate, and 2" thick in the sill plate joist area up the the main floor sub-floor boards. Then I figured I'd put drywall up (knowing there will be an air gap between the interior side of the sprayed foam and the dry wall or would it be better to put some paperless batting in? What thickness would you use?). (There will be a suspended ceiling) What do you think about this approach?
Would it be a good idea to use green board instead of standard drywall?
Thanks a million in advance.