From which they create a screed?
The most common is the screed, for the creation of which the following materials are used:
Cement.
Sand.
Naturally, this is not a final list of necessary building materials. In most situations, engaged in the formation of warm floor, specialists use specialized plasticizers. Cements and expanded clay are used as a means of saving cement. It is worth noting that the content of cement can be different. Here, much will depend on what purpose the flooring has.