Carry out a CM measurement with a CM device or a CM measuring device. The laying of tiles and other materials on excessively damp subsoils can subsequently lead to considerable building defects and damage to the building. Therefore, you should take precautions in advance before taking any risks. Unfortunately, it is you who laid the floor, and who will be held accountable later. Therefore always better to play it safe. A CM measurement serves in the run-up to the installation of the clarification of whether a screed subfloor is already completely dry.