The article discusses the peculiarities of the "water-glass – glycerol" foaming mixture components interaction during foam glass synthesis. The important role of the foaming additive type in the foam glass porous structure formation was described, the main foaming substances were listed. The obtaining and researching technology of the samples was described, the compositions of the initial batches using the "water-glass – glycerol" mixture were developed. It was shown that a material with a highly porous structure and density below 500 kg/m3 can be obtained only with the combined introduction of water-glass and glycerol. In this case, mixtures with a predominance of water-glass in the foaming mixture possess optimal properties. Using DSC, it was shown that the addition of water-glass to the mixture completely eliminates the evaporation of glycerol at lower temperatures and intensifies its combustion at higher temperatures. Thus, the addition of water-glass to the glycerol-based foam glass batch allows glycerol to be saved up to higher temperatures that increases the resulting material porosity.