MasterSeal 521 - A polymer modified cementitious, durable, waterproof coating


MasterSeal 521 is a two-component, polymer modified, cementitious coating that requires only on-site mixing to form the ideal product to provide a durable, waterproof coating to re-surface concrete, masonry, and most other construction materials. 

MasterSeal 521 imparts the natural concrete appearance.

Where is MasterSeal 521 applied?

  • To re-face and even out variations in concrete surfaces 
  • As a waterproof coating for water-retaining structures like water tanks, pols, resevoires etc.
  • To provide foundation protection 
  • As a backing to marble and granite to prevent water ingress, and thus alleviate surface staining 
  • To provide protection to concrete surfaces from carbonation and chloride attack For use on pedestrian walkways in marine areas 

What are the advantages of MasterSeal 521?

  • Excellent adhesion – bonds to porous and non-porous surfaces 
  • Limited flexibility 
  • Suitable for light pedestrian traffic
  • Breathable – whilst repelling water, allows substrate to breathe 
  • Slurry or trowelable consistency; application is still possible by spray Unlike conventional coatings, which require a 7-28 day cure of concrete
  • MasterSeal 521 can be applied to 24 hour-old concrete, thereby giving immediate protection 

Product Information

Technical Data Sheet


MasterSeal 521 GREY POWDER 15KG MSDS

pdf (211,39 Kb)

MasterSeal 521 Liquid 5KG MSDS

pdf (185,78 Kb)

MasterSeal 521 TDS

pdf (456,53 Kb)