High-alkali-resistant polymer dispersion blended with silica sand for pretreatment of indoor mineral substrates, particularly concrete, that are unsuitable for direct application of gypsum plasters due to their low suction and smooth, dense surface. Sopro BK 544 is applied as a suction-control coat and bonding layer between substrates offering poor adhesion and gypsum or lime/gypsum plaster. Particularly suitable for smooth-formed in-situ concrete, precast solid concrete slabs and screeded (i.e. ruled off) precast concrete surfaces.

• For walls and ceilings, indoors
• Sprayable with 2 mm dia nozzle
• Adhesion promoter and suction-control coat
• Bonding layer for gypsum plasters, lime/gypsum plasters and cementitious renders
• High alkali resistance
• Drying time: approx. 12 hours