Is Durofoam a Vapour Barrier

Vapour Barrier. DuroFoam insulation used as the sole thermal insulation does not require a separate vapour barrier to control condensation within the assembly. thermal insulation in a building assembly the temperature of the inner surface of the low-permeance insulation will be close to the interior room temperature.

Is DuroFoam a vapor barrier?

Styrofoam (which is actually a Dow Chemical brand name of extruded polystyrene) is a fairly good vapour barrier. It will not cause problems in the Canadian climate if you put on at least 1-1/2 inch thick and preferably in 2 ft.

Is XPS foam board a vapor barrier?

XPS is manufactured in both an unfaced form or with different plastic facings. However, XPS is considered a vapor retarder, not a vapor barrier. … Innovative applications of EPS and XPS have improved a building’s envelope thermal performance.