The base of the floor
The base of the floor is made of layers of gravel or crushed stone with a thickness of 100 — 150 mm and sand 30 — 50 mm thick. The gravel layer is compacted by a metal tamping, a layer of sand — wooden. A membrane film is laid on the sand, a concrete layer with a thickness of 100 mm and a screed — from 40 mm on top.