The moisture vapor reduction system of the present invention comprises of as a first component the special mineral adhesive, being a hydraulic mineral adhesive, which comprises filling materials selected from the group of mineral fillers and/or plastic fillers and further comprises a binding material composition selected from the group consisting of Portland cement clinker, calcium-sulfo-aluminate and mixtures thereof, combined with an excess of a sulfate providing agent and further comprises as a second component a cover, e.g. a sheet or foil, made out of a waterproof and/or vapor-retarding material.