The possibility of obtaining a foamed aluminosilicate product for construction purposes from the ashes of a coal-fired power plant, cullet, and silicon carbide is shown. The physical and mechanical properties of the obtained foamed aluminosilicates have been studied. The temperature regime and the optimal ratio of components for the production of foamed aluminosilicate were determined. It has been established that in terms of strength characteristics, the obtained aluminosilicate is not inferior to known porous building materials. In terms of thermal conductivity, water absorption, and frost resistance, it surpasses them. It is established that the use of ash with a fraction of more than 300 µm does not lead to pore formation in the system. A distinctive feature of the obtained foamed aluminosilicate product is the closure of the pores, which has a positive effect on its performance.