Before moisture sensitive floorings and floor coverings are laid it is essential to ensure both that the floor is constructed to prevent moisture reaching them from the ground and that sufficient of the water used in the construction is eliminated.
Usually the flooring or floor covering is fixed directly to the concrete base slab or onto a levelling screed laid above it. In either case the amount of water used in the screed material or concrete is more than that required for hydration of the cement used because extra water is normally required to give an adequate level of consistence to the screed material or concrete. After the curing period, it is essential that the excess water be allowed to evaporate. The time taken for this to happen should be taken into account at the planning stage. Estimated drying times are necessarily only very approximate as drying is influenced by ambient conditions, concrete quality, thickness and surface finish. Of these factors, thickness and finish are the most important.