KÖSTER NB 1 Grey 25kg

100% of 100
In stock
£70.00 Ex VAT
£84.00 Inc VAT
Mineral-based, sulfate resistant waterproofing system for internal and external waterproofing.

Waterproof Coating

KÖSTER NB 1 slurry is a waterproofing system that can be used internally and externally to waterproof substrates like masonry and concrete. It protects the structure against pressurised and non-pressurised water, providing an additional waterproofing layer. 

How KÖSTER Tanking Slurry Works

This mineral waterproof coating from KÖSTER contains crystallising and capillary-plugging agents. When these penetrate into the substrate, they develop an intense bond and the capillaries are plugged making it completely waterproof to pressurised water of up to 13 bar.  


This professional product is designed for both new construction and the repair of horizontal and vertical waterproofing. It is suitable for waterproofing concrete (including porous), masonry or cementitious plaster and on shotcrete. This can be in the following places:

  • bathrooms, showers, wet rooms
  • new basements - inside of basements
  • inside elevator shafts, tunnels
  • leaking retaining walls & ceilings
  • tanks, silos, sewage treatment plants, manholes, drinking water tanks

How to apply KOSTER NB 1

This professional waterproofing coating should only be used on substrates that are free of moving cracks. You should also ensure the substrate is clean and open pored to allow the product to penetrate. Substrates need to be wetted or treated with Polysil TG 500 prior to the application of KOSTER NB 1.

The product should be mixed with a slow speed mixer. Add the powder to the mixing water.  

KÖSTER NB should then be applied in at least two coats with a brush or sprayed. If brushing, it should be brushed vertically and horizontally into the substrate.


Full manufacturer’s instructions come with this product.


  • BBA certification for NB 1 (19/5619i1)
  • Easy to apply
  • Long pot life
  • Excellent resistance to pressure and abrasion
  • Chemical and sulphate resistant.
  • Works on masonry and on very porous substrates like shotcrete, aerated concrete and cinderblock

  • Inhibits salt movement in the substrate when used with KÖSTER Polysil TG 500   
More Information
Model W 221 025
Manufacturer Delta Membranes
Packaging Individual unit
Size 25Kg Unit
Dillution as per data sheet
Coverage as per data sheet
Country of Manufacture Germany

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