As a primer for PCI seals and PCI coatings on cementitious substrates, mastic asphalt screeds, ceramic coverings, synthetic resin coatings and wooden substrates. As a primer for indoor floors before applying floor leveling/filling compounds, also when subsequently gluing parquet floors Substrates with adhesive residues from dispersion, reactive resin, water-soluble (e.g. sulfite blue adhesives) and bitumen-containing covering adhesives. Moisture barrier (two applications required) up to residual moisture = 7 CM-% in the substrate for cement screeds (on underfloor heating up to residual moisture = 5 CM-%) when used as a primer before applying floor leveling compounds with subsequent laying of textile and elastic coverings or parquet. Solvent-free according to TRGS 610, no pollution of.