Key Facts

CR166 Flexible Slurry

Flexible, 2-component, waterproofing slurry. For crack-bridging waterproofing of buildings and structural components.


  • waterproof
  • flexible
  • frost resistant
  • strong reduction of capillary absorption of water
  • increases surface protection
  • covers surface cracks
  • compatible with sealing tape
  • can be applied by brush, trowel or sprayed
  • protects reinforced & standard concrete structures


Ceresit CR 166 is designed for waterproofing and damp-proofing of mineral substrates. It can be used for exterior as well as interior waterproofing on deformable and non-deformable substrates. It can be applied on terraces, balconies, in wet rooms, underground constructions, sewage treatment plants, cesspits etc. It can also be used for interior sealing of swimming pools and water tanks (including drinking water tanks) with a depth up to 50 m. CR 166 withstands negative water pressure and its flexibility allows to bridge cracks in the surface.

The coating delays carbonization and can be used as an anti-corrosive layer protecting concrete and reinforced concrete from the atmospheric pollutants. CR 166 passed the tests according to EN 1504-2 standard. It can be used to improve concrete surface protection of different structures and elements such as internal humid areas, garages, pillars and bridges.

Ceresit CR 166 Flexible Slurry is a part of Ceresit cementitious slurries range with Hydroslide Effect.

Step By Step

Substrate preparation

CR 166 adheres to load-bearing, solid and clean surfaces, free from any substances that decrease adhesion (such as grease, bitumen, dust), namely: – concrete (over 28 days old), – cement screeds and plasters (over 28 days old) – rapid-hardening cement screeds CN 87 (over 3 days old) brickwork with full-joints (over 28 days old). Surfaces must be smooth, absorbent and porous. Dirt, existing layers of low resistance and all previous paint coverings, cement and cement-lime plasters, and substances that impede adhesion must be carefully removed. It is recommended to prepare the substrate with a high-pressure water jet or by sandblasting. Static cracks of more than 0.5 mm width should be widened and then filled with Ceresit CX 5 cement. Uneven surfaces should also be levelled with cement mortar. Additionally, sharp edges (slubs) e.g. left by shuttering boards must be cut or ground off. The edges should be chamfered to approx. 3 cm, whereas corners should be rounded (with cement mortar or CX 5 mixed with sand) to a radius of least at 4 cm. CR 166 requires pre-wetting of the substrates before application to the mat-wet conditions (without puddle formation).


The consistency of the slurry should be adapted to the application method: – brush application: fill component B (liquid) into a mixing vessel, add 2 liters of water and stir with a slow-rotating electric drill while adding the powder component (A) – trowel application: fill component B (liquid) into a mixing vessel and stir with a slow-rotating electric drill while addind the powder component (A). The mixture should be stirred until it is completely free of lumps. Leave CR 166 to mature for approx. 5 minutes and then shortly stir the mixture again. Substrate before application should be damp but not wet. First generouns coat of CR 166 should always be applied with a ceiling brush. Subsequent layers can be applied by a brush or a trowel. Sealed surface should be protected against too fast drying and the direct exposure to the sun. If the application of the second layer is also done by brush, it should be done in a crosswise manner on the layer that is already hardened but still damp. Usually, new layers can be applied every 3 hours. Tools and fresh residues can be rinsed with water, but after hardening only mechanical removal of the slurry is possible. If CR 166 is used to additionally protect the reinforced concrete against too rapid carbonization, then it is always necessary to apply the slurry coat 50 cm beyond the area in danger of carbonization. Expansion and working joints as well as corners that cannot be easily rounded to 4 cm radius should be sealed with Ceresit CL 152 sealing tape or Ceresit CL 56/57 sealing corners. These sealing materials are embedded between the individual layers of CR 166. Pipe passages should be additionally sealed with Ceresit CL 53 wall sealing collars. The sealing slurry is ready for foot traffic after only 3 days. However, even after complete hardening the coating must not be directly exposed to heavy mechanical loads.