Koster 21

Koster 21

Koster 21 is a 2 component, solvent-free, liquid applied, elastic, crack bridging waterproofing material with excellent adhesion to dry and moist substrates.

Koster 21 is liquid applied and seamless, which greatly eases application to complicated architectural details. 21 seals against synthetic oils and aliphatic hydrocarbons with high boiling points (up to 2 bar).

Koster 21 does not contain volatile organic compounds (VOC content = 0), is free of polyurethanes, isocyanates, and bitumen.

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Koster 21
  • Positive side waterproofing
  • Fast curing
  • Highly flexible
  • Easy application
  • Seamless application
  • Reflects sunlight and reduces building surface temperatures
  • Suitable for new construction and repair on existing structures
  • Suitable for waterproofing basements (exterior or interior horizontal and vertical surfaces)
  • Suitable for indoor and outdoor use
  • Not resistant against substances with high aromatic hydrocarbon contents such as benzene, xylene, toluene, etc. In case of questions contact our technical support team.
  • Resistant to occasional foot traffic, aging, hydrolysis, UV-rays, frost, and salt
  • Once first layer has cured, can be covered with subsequent layers
  • Installed sheets should overlap by at least 5 cm
Product Details
Koster 21
Product Code:
DMS 244
20kg bag
Coverage Rate:
6.67m² (3kg/m²) - 8m² (2.5kg/m²) 2 coat application
Koster 21
  • J30 Liquid applied tanking/Dampproofing

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