Hello All,

I would appreciate any help on pointing me in the right direction. I am in the process of finishing my basement which will convert it from an unfinished space to a finished space. It is a walk out basement with about 50% of the walls concrete below grade and the other 50% is standard framed construction with 2”x6”, Osb sheathing, and velvet house wrap under vinyl siding. These walls are above grade. The buildee left faced r-19 fiberglass insulation in these cavities.

For the concrete, I am leaning towards 2” XPS behind 2” x 4” framing with unfaced fiberglass or mineral wool in the walls. This would be for the walls that would be finished space. For the mechanical areas I was going to do 3” foil faced Thermax to save on some space.

I am really struggling on what to do with the framed walls above grade. I was lead towards foam board and batt by putting in 2” XPS board in the cavities, and the 4” of unfaced fiberglass or mineral wool insulation in the wall to complete the installation. The XPS board would be sealed with spray foam. My  other option is to just replace it with faced fiberglass unless anyone has some other ideas.

Another option I am considering is just using The aluminum faced thermax everywhere but I am not sure if that would create double vapor barriers / moisture problems anywhere.

Any help is appreciated. Basically, I am looking to see if the foam board and batt strategy is even worth it if I can use thermax in lieu of cos behind / in the walls.

Thanks again.