Masonry of autoclaved aerated concrete blocks is used in the construction of exterior and interior wall enclosures of modern buildings for both high-rise and low-rise private types. However, the construction of walls from small gas-concrete products (blocks) it is necessary to use the cement mortar (fastening in masonry blocks with each other). Mortars that are usually used for that purpose is either cement-sand mortar or thin-bed adhesive cement. Due to the fact that the thermal conductivity of cement mortar used to bond masonry blocks is much higher than thermal conductivity of the cellular concrete grades with density D400-D600, the presence of joints in the masonry cement leads to the formation of "thermal bridges". Thus, masonry joints cause additional loss of thermal energy which, when using thin glue can reach 10%, while using sand-cement mortars - 30% additional cost of heat energy compared to cellular concrete. Additional heat losses lead to a need to increase the rated capacity of the heating system and as a consequence, an increase in consumption in the building heating energy during the heating season. For this reason,to further improve the laying of concrete blocks it is required to develop fastening masonry structures characterized by low values of thermal conductivity. One of the options for improving the thermal insulation properties of aerated concrete masonry units is to use one-component polyurethane adhesives with thermal conductivity much lower than thermal conductivity of autoclaved aerated concrete blocks.