Retroactive waterproofing in existing buildings needs to be done with mineral waterproofing systems. They have excellent bonding characteristics to mineral surfaces and also will not detach from wet and moist substrates.
The substrate must be sound, solid, and free from bond inhibiting agents. Existing coatings must be removed, joints must be raked out, and all loose particles must be removed. Prime with KOSTER Polysil TG 500. It hardens the substrate and reduces the mobility of salts. Masonry repair and the installation of a fillet at the wall/floor junction is done with KOSTER Repair Mortar Plus.
KOSTER NB 1 Grey is used as the waterproofing layer. For a faster installation, use KOSTER NB 1 Fast. To harden the material, KOSTER Polysil TG 500 is sprayed on top of the slurry. To get a lighter surface finish, use KOSTER NB 2 White for the final coating.
Pipe penetrations are waterproofed using KOSTER KB-Flex 200 and sealed with KOSTER KB-Fix 5.
In the case of damage to basement walls caused by moisture, KOSTER Restoration Plaster should be applied. KOSTER Restoration Plasters are specially designed for the restoration of masonry with high salt and moisture contents. KOSTER Restoration Plasters help to dry out the wall and absorb remaining salts. They do not contain lime or gypsum, are open to water vapor diffusion, and create a healthy and comfortable room climate.
Before the application of the main plaster coat, a plaster key made from the chosen KOSTER Restoration Plaster mixed with KOSTER SB-Bonding Emulsion is applied to provide a larger surface area and ensure an optimal bond to the substrate. KOSTER Restoration Plasters are available in different varieties (grey, white, fast and light). KOSTER Restoration Plaster 2 White is often used in older buildings without subsequent painting. KOSTER Restoration Plasters can only be painted over with breathable (open to vapor diffusion) paints such as KOSTER Silicone Paint White or KOSTER MF1.
Always adhere to the specifications in the respective Technical Guidelines.