DixieDeere - 12/29/2020 10:28

I'm not saying I'm up on the vocabulary, and I built and researched in 2013 so it's been a while.  All I'm saying is that R value as it's assigned to fiberglass, cellulose, or even concrete block walls is not applicable to foam.  When the industry started out an R value per inch was put in place for code enforcement.  What I found out, and what my installer complained about, was he had to put more insulation on unnecessarily due to the code, and in many cases had to use closed cell at a higher cost due to space restrictions.  For example a 2x4 would have to be covered with 6" and couldn't be shaved if using open cell, so closed cell had to be used.