Will Two Layers of Exterra Still Be Permeable?
WILL 2 LAYERS OF EXTERRA STILL BE PERMEABLE? No. Two layers of Exterra will not meet the minimum requirement of being “permeable”, which is 60 ng/Pa-s-m2, or 1 perm. A single layer of Exterra maintains it’s breathability up to a maximum thickness of 2” (71 ng/Pa-s-m2 or 1.2 perms at 2”). Exterra panels are laminated […]