Hello GBA,

What is the ideal perm rating for insulation being installed on basement walls in Zone 5? Is there a strong preference toward either XPS, EPS, or a closed cell spray foam? Lets assume that all basement moisture issues are taken care of.

I believe that controlling the air movement is the most important component of a dry basement assembly, but I also do have concerns about vapor diffusion and condensation at the block.

So many opinions going around out there….

Thanks!

-Art