The manufacturer calls it R-4, but it is really only R-1.1 plus the radiant barrier. They are assigning a value of R-2.9 to the radiant barrier under some choice of standard conditions. But the value of that radiant barrier varies according to conditions. Anywhere it is up against another material, or anywhere it gets dirty, the radiant barrier has no insulating value.jclemens wrote:I initially used the same cheap pipe-insulation that is common, but I didn't really like it, plus the R value (insulation ability) is better on this metallic bubble wrap. According to the lowes website, this stuff is R4, vs the foam pipe insulation which is only 2.4
Cheers, Wayne