You need expert advice, not hit or miss DIY suggestions. I always turn to the Building Science Corp. web site to understand the science behind the issues and what solutions work in the real world. A good article for you to start with regarding basements issues is Building Science Digest #103: http://buildingscience.com/documents/digests/bsd-103-understanding-basements

I suspect what you will end up with is some type of foam on the foundation/exterior walls, then unfaced fiberglass, then interior drywall with a latex paint. Enjoy your reading on the BSC web site, there is a ton of info there!

Rick

Given that you already have the studs up, I recommend you use roxul. It is water repellent, fire resistant, made from stone, and is thicker than your fiberglass. This stuff can be found at home depot or lowes. I did a lot of research on insulating my concrete basement walls. I first applied owenings corning formular 250 form product to the concrete wall which was a R-10. Then I installed my studs and I will now put roxul comfort batt of R-15. The basement was very warm just with the owenings corning formular 250. I also insulated by joist bands with roxul. I would never go back to fiberglass insulation. Check out the roxul reviews on home depot and lowes websites. Good luck to you.

I found the same situation regarding conflicting data on foam and vapor permeance (both from building science sources). I believe the newer thinking is that concrete doesn't need to "dry" to the inside. It's naturally damp. It wicks. Accept it and move on. It's not really going to STAY dry unless you live in the desert southwest and then maybe not even then. Assuming you don't have flooding, put the tightest seal you can against that wall. Think:
- How am I going to manage moisture and airflow so R-value doesn't matter as much?
- How can I make sure water (yes, there is always water in concrete) doesn't make if through into the wall.

I'm choosing the same components as hime but with thinner XPS since I'm in the south, below grade, and only really need it for vapor/thermal break. The R5 XPS sheets and the R15 Roxul batts are within about $40 for the same square footage, but they perform different roles, so I'm using both.

I used blocks of XPS and can-foam in the rim joists to completely seal them off. It was a little slow, but not bad to do with some music and a beer. That one week worth of evenings made the biggest single difference in noise, leakage, and temp control in the basement (it's really the only part above grade). In a basement, fiberglass's few advantages (cost and cost) are vastly outweighed by the disadvantages (glass fiber, difficulty to get installed just right, breeds mold, holds moisture, doesn't block airflow). Don't think I'm just fearmongering... It's possible to use fiberglass in a place like this and be really meticulous and have it work fine. I've seen lots of friends and neighbors use it and don't have giant mold issues....yet. I'd rather spend a little more on mineral wool for the piece of mind.

Permanence really doesn't vary that much between different thicknesses of XPS. Moreso in EPS since it lets moisture through pretty easily. As long as you have enough to keep the inside temp of the foam above the dewpoint for the coldest average climate days in your region (google-able on how to calculate that), you should be good on that.

Just think of it as a system, focus on keeping the envelope tight and making sure there are no gaps where cool meets warm (or cool meets insulation, more accurately). Pay attention to the little details where dissimilar things meet each other. Those are where the problems happen.

Hime, my experience has been similar. My preferred HVAC contractor also does foam, weatherizing, home performance and bid about 7k for closed-cell icynene for my space....but I'd have to frame it all first and would need to get ALL the items out of the area and I'm still using the other end of the space for mechanicals and lots of storage. XPS sheets + tape + foam board adhesive + can foam + MDF for fire blocking at the top all equals about 2k. My labor is worth a lot to me, but not THAT much :)

Thank you, all! This has helped!

I am only looking to make changes to the framed portion above the foundation (it is a walk-out so the only place I have the mold issues are the above grade half/full walls in the basement. It is hard to figure out exactly what to do because almost all of the advice I find online is related to below-grade walls sitting in front of the foundation.

formulaross20, I completely agree that I need to talk with an expert. I am just not sure how to find a reputable basement insulation expert vs. someone who wants to do the job and doesn't care about 10 years from now when I find out I have mold there. The majority of the places around me appear to be "Basement Systems" dealers. Any advice on how to weed out the non-experts or what to look for?

dgeist/Hime, Thank you for your input! It sounds like you guys encased your foundation walls w/ the foam board and then put framed walls up against that. If that is right, my situation is a little different because I am trying to just fix the problem on my walls sitting on the foundation (half/full walls leading to the walk-out). Perhaps my framed walls on the foundation can/should be handled in the same way your rim joists were handled? XPS + Spray foam + Insuation to fill the rest of the framed wall, but I may just see if I can get some contractors to come out and see what they suggest before I decide to allow them (or then just do it myself if it is simple enough).

Thanks!

There are some really good examples for various scenarios available here:
http://buildingscience.com/documents/digests/bsd-103-understanding-basements

Figure 10 might be right up your alley, and the best place to insulate may be on the outside if it's accessible.

Thanks. I agree. Unfortunately, I can't insulate on the exterior as that would require me to completely redo the siding of the house. I am thinking my best bet might be what it has shown in the circle on figure 10 for the rim joist when exterior insulation is not an option, but for the entire area between the studs on my framed walls.

I believe the newer thinking is that concrete doesn't need to "dry" to the inside.

Yes, Dr. Lstiburek changed his mind after some gentle prodding.

The tightest basement I've done had 3" of closed cell spray foam (ccspf) top to bottom of the nine-foot walls. And since the homeowner didn't want the ceilings finished, only the walls, I had to spray a couple of inches of plaster at the top of the wall as a fire barrier. (Other municipalities will not necessarily accept this as a thermal/fire barrier.)

What did you end up doing? i have the same issuenin Southern Ontario. Contractor wants to use spray foam but I want to use Rock Wool. How to deal with the moist sheathing?