Air and vapour barriers
The Complete Guide to Smart Vapor Barriers and Vapor Open Membranes to Help Keep Walls Dry
...ProClima Intello Plus or Siga Majrex typically offer a vast range of variable permeance, often shifting from less than 0.7 perm when dry (Class II vapor retarder) to over 13 perms when wet (vapor open). This large range provides the maximum safety and drying capacity for the wall assembly.
The Perm rating: The perm ra...
