KÖSTER NB 1 Grey is a mineral sealing slurry for waterproofing of mineral based materials from the positive and negative side.
The material is waterproof when being pushed up against the building structure, but also won´t be pushed off by rear-facing water pressure. It bonds so tenaciously to the substrate that it can resist 130 m of water column, or 13 bar of negative pressure.
How does KÖSTER NB 1 Grey achieve this remarkable feat? It´s because not only does it mechanically bond to the substrate, it also chemically bonds to it. As we all remember from grade school, the chemical bonds in nature are much stronger than the mechanical ones. KÖSTER NB 1 Grey does not merely adhere to the substrate, but becomes an actual part of a composite system, it becomes a permanent part of the structure itself.
The high-quality amorphous micro-silicates in the cured slurry can react with calcium hydroxides and water to create Calcium Silica Hydrate (CSH) crystals that plug pores and heal cracks.
KÖSTER NB 1 Grey does not contain sodium-based silicates, which CSH crystals can be dissolved over time, and can attack the reinforcement steel. That is an important feature compared to cheaper materials in the market.
Aside from this, KÖSTER NB 1 Grey also has Additionally, since KÖSTER NB 1 Grey has its own calcium hydroxides and does not rely on them being present as in a healthy concrete, our product can be applied to a wide variety of mineral substrates, such as concrete, brick, shotcrete, aerated concrete, many natural stones, and cinderblock. It is VOC free and has drinking water certification.
This is an important advantage of KÖSTER NB 1, in contrast to crystalizing waterproofing slurries that need calcium hydroxides in concrete, because these subestances my not be present in older concrete due to carbonization.
By replacing part of the mixing water with KÖSTER SB Bonding emulsion or just mixing it with KÖSTER NB 1 Flex, helps to prevent premature drying out (it´s a built-in curing compound) and makes the slurry creamier and easier to apply. It also provides some flexibility.
KÖSTER NB 1 Grey is one of the most outstanding products in our product range. For area waterproofing, in new or existing construction, from the inside or outside, in drinking water environments, in combination with horizontal barriers and restoration plasters, or concrete protection systems, it is also one of our best sellers.
