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. It is liquid applied and therefore seamless, which greatly eases application to complicated architectural details. Due to its UV stability it is suitable for indoor and outdoor use.

The white colour reflects sunlight and reduces building surface temperatures. The fast curing coating is highly flexible, resistant to occasional foot traffic, ageing, hydrolysis, UV-rays, frost, and salt.

It seals against synthetic oils and aliphatic hydrocarbons with high boiling points (up to 2 bar). It is not resistant against substances with high aromatic hydrocarbon contents such as benzene, xylene, toluene, etc.

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

Fields of Application:

21 is a waterproofing material for the positive side waterproofing of basements, concrete slabs, in tanks, on flat roofs, underneath tiles, on terraces or balconies, and similar applications.

It is also suitable as a protective coating against mineral oils and aliphatic hydrocarbons. It’s suitable for the protection of surfaces in facilities with chemical and mechanical demands on the coatings, such as containment and skimming tanks. It also bonds well to a wide variety of substrates, including: masonry, concrete, screed, plastics, metal, and bitumen.

• Waterproofing balconies and terraces,
• also before installing ceramic tiles.
• Waterproofing Basements.
• Waterproofing Roofs (with occasional foot traffic).
• Waterproofing Tanks and basins.
• Carbonisation inhibiting.
• Protection against aliphatic oils.
• Waterproofing old bituminous surfaces (renovation).
• Waterproofing concrete slabs.

Consumption Approx. 2.5 – 3.0 kg / m² Do not exceed layer consumption by more than 100%.