02/18/2018
Another good article on v***r barriers. " Most codes require a v***r barrier of one perm or less. Researchers, however, have found that air leakage generally moves a lot more moisture than diffusion. Therefore the air barrier is much more important than the v***r barrier. So if you’re concerned about really keeping moisture out of your wall and ceiling cavities, you ought to be paying close attention to the air barrier. That means using
1.) a continuous, airtight membrane, and/or
2.) a lot of caulk, foam sealant, and gaskets to block up any significant leaks (see “Air Sealing Details”)."
Answers to the most common questions about moisture migration through walls and ceilings