My Basement Concrete Form wall already has insulation of approx. 3 1/3 inches over the concrete form walls. This insulation has a white vapor barrier. I want to put in a 2 X 4 Stud wall and insulate with rolled R-21. Should I remove the insulation on the Concrete form wall and then build the stud wall or just leave the current insulation and build the wall and insulate it also?

I live in Colorado Springs, Basement is heated, very low humidity, basement is dry, no unusual problems, just basement is cold in the winter.

 

I am no expert, but from what I have read, just leave the insulation in place on the concrete wall and build the framed wall next to it. Just do not build the new wall too close--there needs to be room for the insulation to be fitted nice and loose.

As for insulating the new wall that would be overkill.

Good luck. There has also been some discussion that the vapor barrier on the original insulation would be better off if it was sliced to allow for moisture escape. But that would be a lot of work. Just do a search on this forum and you will find out more information.

 

As for the cut in the origional vapor barrier, My kids have taken care of that by slitting it in various places. I have used insulation tape to cover these areas with 6 mil Poly. We are taking big slits, the kids seem to like how easy it slices.

 

Used to live in the Springs myself, bout 20 yrs ago, definitely not a humid place and being from the midwest, I thought it to be a very tolerable climate.

I'd leave what insulation you've got on the concrete walls and frame the new walls up in enough to allow room for the batted insulation to sit in the stud cavities. Awound here I use R-19, they might call for a bit more in your region of the country. You can look up DOE recommendations for your area on their website. Here's a link,
http://www.ornl.gov/sci/roofs+walls/...on/ins_15.html