Foam blocks have a sufficient fortress so that they can be used even for black floor laying under the cladding of ceramic tiles or other facing materials. In the case of the use of foam blocks for black flooring, waterproofing and cement screed are produced. For the installation of the floor of the first floor of the house, a wet soil seizure and backfill are made with a stone layer of stone and gravel and sand, which will create the first barrier to the floor for underground moisture.