Experimental research findings are reported on the characteristics of physicochemical processes at different stages of fire development and suppression. Fires involving solid materials like wood, cardboard and linoleum were investigated. The minimum necessary and sufficient volumes of firefighting liquid (water with different additives, e.g., a foaming agent, bentonite, bischofite, etc.) and their spraying times were identified. Differences in spraying characteristics (droplet velocities, sizes and concentration) were recorded. A relationship between the spraying characteristics of fire extinguishing agents and efficiency of fire suppression was established. Correlations were identified between the operational characteristics of fire detectors during fire suppression involving several fire extinguishing agents. The most efficient compositions in terms of fire suppression time and extinguishing agent consumption were found for typical indoor combustible materials. Mathematical equations were derived to predict the key characteristics of fire suppression.