Concrete Covering for electrical floor heating

Hi I am buying a house in Chatreuse in Isere and am at the moment planning everything. I have found most things I need and suppliers, but I am struggling to find the correct french term to find a company that will do the following I need a 3cm specialist concrete scree to be poured over the laid electrical heating mats, and levelled - for 3 large rooms (all about 30m2). And I cannot for the life of me find the generic french term that will describe that sort of company any hints will be gratefully received merci Andy