Prior to installation, it should be verified whether the installation sub-layer is suitably prepared. This means that the subfloor must be dry, even, clean and able to provide a supporting surface. Suitable sub-layers are all types of screed including hot water-heated screed, wooden chipboard structures, fibreboard, PVC, linoleum, natural stone boards or ceramic tiles.
The sub-layer must be prepared for installation, which means the subfloor must be dry, able to support loads, even, and clean. Use a max. 2 mm gauge (vertical deviation) at 100 cm intervals. Larger deviations should be handled with suitable measures (e.g., with self-levelling compounds).