I am finishing my basement. Ive installed additional hydronic piping for the heat. Ive installed 2x3 studs, and am planning on R-11 fiberglass insulation.
1st question: Is the kraft paper on the insulation good enough for a vapor barrier, or should I also installed 4 or 6-mil poly sheeting?
2nd question: Ive heard two trains of thought on completely sealing the wall cavity at the top, above the drop ceiling (where there is no top plate). The first says leave it open to allow any moisture that develops to breath out of the gaps and thus not get trapped. The second is to completely seal it to prevent any moisture from getting down into the wall in the first place. Regarding the latter, what about possible moisture coming through the wall from the foundation side? Does this then say to seal the cinder block wall with an epoxy sealant?