We choose the insulation with a thickness of about 100 millimeters and lay it on top of the finished timber. In the event that foam or polystyrene foam is used in the roals of the insulation, then the slabs of this material should not be less than 10 millimeters on both sides — this also applies to the junction of the material. In order for the insulation does not fail, it is attached with small cloves. All the resulting cracks are poured with mounting foam. The result of all these works should be a monolithic floor that will not pass air from the street. Gently, carefully remove all the excesses of dried foam with a knife or hacksaw. After the entire procedure, the floor itself is directly laid on the finished lags — as it will be, you decide.