Before starting any flooring works - substrate should be properly assessed and prepared. Substrate preparation consist of few very important steps to be done before proceeding further with any flooring installation works.
The floor installer must ensure that the floor covering can be installed without the risk of later bumps and blisters. It is therefore part of his duties to check whether the substrate is sufficiently dry.Moisture is measured by CM method. Please refer to local norms reg. moisture values to be met before any further flooring installation works are done.
The substrates must be clean, crack-free, sound, dry, free of substances that may impair adhesion (such as grease, bitumen, dust, paint or adhesive residues, etc.) and must comply with the relevant local standards. The existing dirt, weathered layers and paint coatings of low strength should be mechanically removed. Removing of old material residues is done with screed-grinders, shot-blasters or other special tools.
Cracks can be expertly repaired with CN 89. Unevenness in the substrate should be filled with CN 83 or CN 91.
The next important step is priming. Absorbent substrates should be primed with the agent Ceresit CN 94. Before levelling compound installation - residual moisture in the substrate and its strength must be carefully checked. In case of moist or weak substrated special primers have to be applied.