Modern construction market is experiencing a shortage of highly efficient thermal insulation materials. Alkali-silicate raw mixtures in combination with high-performance fillers currently make it possible to create porous heat-insulating materials with unique properties: rigid cellular structure, specified geometric dimensions and shape, low thermal conductivity, incombustibility, high processability, environmental friendliness, etc. at a relatively low cost. The use of such heat-insulating materials in construction allows solving the problems of energy saving, accessibility and cost-effectiveness. The article considers possibility of obtaining heat-insulating material based on sodium silicate (silicate glue "Polipax") and natural material -flasks from Taskalinsky deposit of West Kazakhstan region. Technical characteristics of Polypax glue are given. Using a scanning electron microscope, elemental, chemical, and oxide compositions of the flask were studied. A recipe for a heat-insulating composite material (HCM) has been compiled.To assess the quality of the obtained HCM, its physical and mechanical characteristics were determined: density, water resistance, thermal conductivity, strength. Samples I-II in terms of density and strength showed the best results, and samples III-IV differ slightly from the technical conditions in terms of the studied indicators. It has been determined that the obtained HCM using flask as filler has a positive effect on the performance properties of the heat-insulating material, and is also economically viable, because local raw materials are used. Thus, it is possible to use flask from Taskalinsky deposit of West Kazakhstan region as filler for heat-insulating material.