Originally Posted by Bob Mariani
Unfortunately the codes have not kept up with the latest science and as such you will be building a wall guaranteed to fail. Example: Warm air moves into this wall and hits the cold foundation wall. It condenses.... what are you doing to stop this and what are you doing to remove this moisture.
The latest science doesn't seem to have much consensus around best practices for vapor barriers. I actually wanted to do XPS or something of the sort, except I couldn't get enough R value out of it to meet code within a reasonable thickness.
I'm no contractor, but I'm pretty good at research. The exterior is sealed up pretty well, and I Drylocked the entire interior. The main concern in this region is expansive soils and capillary action during that once in a decade rain storm, which the above addresses.
Winters get cold but relative humidity stays low and condensation is a relatively low risk in basements here. The insulation is kraft faced batts w/MR drywall and that's it. No vinyl. For every one person who says put the vinyl here or there, I could find a person who says the cutting edge science is that vapor barriers actually cause more problems than they solve; that some condensation is inevitable no matter which way you go, and that it's better to give it a way for moisture to evaporate (rather than trap it behind the sheet). My entire building department and some people I talked to in the biz all agree.
Just for laughs b/c I'm curious about it, I'm going to install some sensors behind the framing so I can check on moisture levels from time to time under various conditions. Plus I saved up a bunch of desiccant packets from various packages...couldn't hurt to throw those in there too :-)