Working from scratch with a bare wall. What do I do? 3 hardware stores have told me 3 different things. We have very cold winters here. Looking for cheapest and highest R value. contractor next door says 2 layers ridged R5, overlapping and taped...2x4s...then gypsum board. He says I don't need a vapor barrier.
Best place to go for this sort of information is buildingscience.com. This set of documents on basements will have lots of useful guidance.
Read this answer I provided here (this question is likely a duplicate of it):
Broadly speaking, there are two ways to answer this:
- do it the way code states
- research and do it the way you want to do it, potentially having to convince the code folks it's the better way.
I chose the latter after doing a lot of research (see above link) that states that vapor barriers are probably a bad thing in a basement. Code dictated that there be a barrier, and as such I had to spend a chunk of time doing a lot of documentation and providing citations to other research to convince them otherwise (I was able to finally convince them).
To summarize, I generally agree with your neighbor, and would suggest a) using metal studs instead of wood (mold can't grow on metal + it's really easy to work with) and b) upgrading the wall board to a paperless product such as densarmor (which uses a fiberglass surface instead of paper).