I'm finishing off a section of basement and my insulation guy says to use unfaced fiberglass batts in the exterior wood stud walls, framed a bit off the concrete foundation. Does this make sense? I was expecting to have a vapor barrier in there somewhere, or maybe even foam board, but he says those just trap water and grow mold. Things have changed since I last did any insulation, I guess! Any recent experience with this out there? Thanks! --67.172.xxx.xxx

Just did an insulation on a brand new basement.... 6 mil plastic on the concrete, that traps any moisture from coming into the basement or insulation from the walls. A stud wall built a few inches away from the concrete, unfaced fiberglass in the stud cavities. I also see foam board put against the concrete and the studs built in front of that. --96.236.xx.xx

Mold likes warm wet places with no air circulation. You can figure that out yourself where it will be like that in those layers you are describing. --73.33.xxx.xxx

In addition to the insulation you should consider adding some ventilation to the space. The fan for this ventilation needs to be controlled by a humidistat to automatically help remove any excess humidity. In my basement laundry rooms of my multis, I have an exhaust fan with an adjustable humidistat as well as a temperature control. They do a great job keeping the excess moisture out of the rest of the building. --72.93.xxx.xxx

As an energy auditor I have my opinions on how a basement wall should be constructed. However I am in NH and you are mid Atlantic and you have different variables than I have. There have been many studies done. Building science is a pretty young industry like the climate warming dudes. My friends in the industry are still experimenting on composition of the wall components and materials to get the right air sealing , moisture prevention and insulation. However, to get your answer ,you need to do YOUR research for your climate and avoid taking any advice from a common builder / contractor. They give you what their daddy taught them. Betting they haven't been to any symposium on wall component interaction. - You must TELL HIM what you want. Building Science Corporations has an article on Masonry wall insulation. --24.34.xx.xxx

good luck --65.188.xxx.xxx

This is all very helpful! Thanks! Will do some more reading. --67.172.xxx.xxx

I think you need to plan well, any product that can absorb water will and even condensation will make water, I think the thin foam with fiberglass but allow a few inches at the bottom because leaks can happen and they stuff on the inside can not hold back water. --76.188.xxx.xx

Laura, No matter what the science Whizzs come up with ,just use your common sense,that'll go a long way to solving the dilemma.........charlie............it always does........................................ --174.199.x.xx

Thanks for all your thoughts and guidance, too. --67.172.xxx.xxx

Solid board has a higher R factor per inch along does not absorb water. There are methods of attaching insulation directly to concrete then can install mold resistant drywall. Insulation board has R factor 5 per inch then higher for the silver back board of R 6. With two inches of board R 10 is achieved. Insulation is about keeping the heat in with a minimal loss of space. There are videos on You Tube about insulation so check some videos then see how things are done before making a decision. Fiberglass should be last option where Roxul is better. --147.194.xxx.xxx

Careful Laura - generally inspectors are people that failed at Contracting or in many cases the local fire chief becomes the inspector with zero background in the trades. Your 6" Concrete wall probably has a waterproofing on the outside. I doubt that changing the frost characteristics of the wall component will have any effect in our lifetime. However Concrete is like a sponge with regards to heat and moisture so changing the environment for that wall component does what? I won't be around on this earth long enough to learn what happens to 6" of concrete. However, when I am asked to consult on our 200-300 year old grand building here in New England I see people doing things that will kill the building in 20-30 years - moisture is an evil thing. I will be around to tell them "I told you so". --24.34.xx.xxx