Is a vapor barrier still required for above-grade Quad-Lock walls?
No. Quad-Lock ICF walls are ‘High Mass’ walls (as opposed to Cavity walls like wood-frame) which don’t need vapor barriers. And the low permeance of the foam and concrete provide a natural barrier against air-borne moisture and air infiltration. This also means that air-borne pollutants, dust, and pollen are kept out of the building by Quad-Lock walls.
