The subfloor must be dry, clean, hard and smooth. It may have irregularities with a tolerance of 5 mm over a length of 3 m. The floor may not slope in any direction by more than 25 mm per 2 m. Even though Parquetvinyl is water-resistant, it does not serve as a moisture barrier. Any loose boards must be fixed, cracks in concrete must be filled. Read all the conditions in the installation instructions.