Check
the consistency of the substrates and the quality of the laying
surface
The most commonly used laying surface consists of a floor rough with
a uniform thickness of at least 4 cm. It is possible to use for the
substrates: cement-based traditional materials, which are the least
expensive but have longer laying and drying times, anhydrite
(anhydrous gypsum) based materials, which are often self-levelling
thereby allowing a good laying surface to be created fast, and
special hydraulic binder-based substrates with suitable additives for
quick drying. An existing floor (provided it has certain
characteristics as described later on) or a suitable base made in
panels of special materials that are usually based on wood, may also
be used as a laying surface.