It is proposed to modify the method of obtaining self-compacting masses by changing the nature of the compacting component ― from expensive and environmentally unsafe polystyrene to a burnable plantbased additive that can self-absorb shrinkage moisture from the molding material enclosed in a hydraulically closed volume. At the same time, part of the mixing water under pressure penetrates into the clay particles with pre-modified physicochemical properties of the surface, forming a semi-permeable shell. Ill. 3. Ref. 3.