KÖSTER Waterproofing


With over 35 years of experience in the waterproofing industry KÖSTER BAUCHEMIE AG is an industry leading manufacturer of high-quality waterproofing products. Koster UK have gained our trust over many years of successful work, their products continue to provide our technicians with the best tools in the trade to complete their projects. Below is an overlook of some of our most used Koster Products:

Koster NB1 Grey waterproofing Slurry

Koster NB 1 Grey Crystallizing mineral waterproofing slurry system is designed to seal against pressurized water (>13 bar). This product is a mineral coated waterproofing slurry that contains crystallising and capillary-plugging agents.

Koster NB1 can be used for remediating against ground water, non-pressurized water and pressurized water. NB1 is best in class for its resistance to high pressure water and abrasion. Koster NB1 Grey Waterproofing Slurry is applied using either a brush or our own specially designed Koster spraying machine, the advantage of which is that the spraying machine applies the product under pressure and greatly reduces the overall time of applying the slurry system with a high quality evenly spread surface.

Koster Repair Mortar Plus 

Koster Repair Mortar Plus is designed to specifically treat weak areas of construction where water and pressurised water may be able to infiltrate a structure. Repair Mortar Plus is a highly watertight, fast setting, and slightly expandable product which provides excellent adhesion to all substrates including old building materials.

Its purpose is to be used for making watertight repairs and touch-ups. It is often applied to help combat against pressurised water via the creation of a wall/floor joint fillet, becoming part of a cementitious slurry system along with NB1 Grey.

Koster SB Bonding Emulsion

Koster SB Bonding Emulsion is an elasticizing synthetic-dispersion for universal use in mortars, plasters, sealing slurries and concrete.

SB Bonding Emulsion is a universally useable synthetic liquid that is designed to be used with all cementitious mortars, plasters and sealing slurries.

When Koster SB Bonding Emulsion is added to a mineral based product, the synthetic liquid increases the elasticity and flexibility and also reduces water absorption. 

Often used as part of our system with Koster Repair Mortar Plus, Koster SB Bonding Emulsion is waterproof in its own right, meaning that it can not be washed away or rained off. 

Koster Polysil TG-500

Koster Polysil TG-500 is an anti-lime solvent product which reduces the movement of free lime within a structure’s substrate. It is a deep penetrating primer for damp, salt-containing substrates and an anti-lime treatment for new concrete which also acts as a liquid hardener for sealing slurries. 

Polysil TG-500 contains differing Polymers and Silicates, this product not only reduces the amount of free lime finding its way into a Cavity Drainage System, but it will also greatly improve the water resistance of the basement structure by absorption into the structure and locking in the free lime.

This product can be applied by either brush or spray. 

Koster Crisin Cream – DPC (Damp Proof Course)

Koster Crisin Cream is a retroactive DPC (Damp Proof Course), damp proofing against capillary rising moisture. It can be applied inside and/or outside a structure.

This injection DPC cream is based on resin/silane which protects against capillary rising moisture/rising damp (wicking moisture). Crisin Cream is resistant against any moisture/salt content.

Koster Quellband

KÖSTER Quellband is a sodium-bentonite based water swellable joint tape with an alkalinity activated surface coating which stops premature swelling of the tape on the building site.

Koster Quellband is used to provide a stop to water ingression within concrete construction joints. The Quellband strip is nailed onto where the existing joint face is before the concrete is poured. Any water leak through the joint then activates the Koster Quellband which then reacts and breaks down, forming a paste which seals the crack and prevents the leak permanently.

Koster 21

Koster 21 is a 2-part, solvent free, elastic liquid applied, crack bridging waterproofing system that features superior adhesion to dry and moist substrates.

As Koster 21 is a liquid applied product, this greatly improves the use and application to complicated architectural details. Koster 21 also seals against synthetic oils and aliphatic hydrocarbons ectural details. 21 seals against synthetic oils and aliphatic hydrocarbons that are found in alkanes.

Koster 2in1 Crack Injection System

Koster 2in1 Crack Injection System is designed to stop active leaks and seals crack and construction joints permanently. It is used as an injection into dry and wet cracks. The product can also be used for filling voids within construction.

2in1 Crack Injection System reacts with water, it is an elastic PU-injection resin. When the product comes into contact with water, it reacts to form an elastic foam material. When it is injected under dry conditions it creates a solid body of elastic resin. The product remains in an elastic state after its initial reaction, thus meaning it can follow any movements within a crack or void, utilising its elastic polyurethane solid resin, meaning that there is no requirement to follow-up injections or treatment.

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