din 18157, Part 1 authoritative. Prime absorbent surfaces with ASO-Unigrund. Calcium sulfate screeds must be sanded, vacuumed and - like all Calcium sulfate-bound substrates must be primed with ASO-Unigrund/ASO-Unigrund-S (MV 1:1 with water). Should be used on calcium sulfate screeds If large formats are to be laid, we recommend priming with ASODUR-V360W due to the greater spearing effect. Heated screeds must be installed before covering work be heated according to the recognized rules of technology. To assess the readiness for covering, a moisture measurement must be carried out using the CM device. The CM measurement is in accordance with the current work instructions FBH-AD from the technical information “Interface coordination in heated floor constructions” A highly deformabl.