I really don't know how is named this material in English but I have to prevent heat lost through it. I assume that it is named mosaic, but I might be very wrong.
Ideally I'll like to have the floor heated by a hydronic system. Do you have any idea about what materials to use and which added to the solution doesn't result in a too height floor?
PS: mine looks like mosaic tiles from this link. It is definitely polished and made of cement and small stones.