The results of studies on the development of vermiculite concrete composites with application of volcanic ash and pumice are presented. The composition of cement fibre vermiculite concrete fire resistant composites is offered, which allows reducing the consumption of Portland cement and simultaneously increasing their flame retardant properties. The use of basalt fibers in composites can improve the strength, fracture toughness and fire retardant properties of the coating due to the perception of tensile thermal stresses during the fire. Replacement of cement up to 30 % by weight with volcanic pumice fraction d < 0.16 mm significantly improves heat-resisting properties of cement stone with a simultaneous increase in flexural strength and no significant loss of compressive strength. Experimental and theoretical studies of fire resistance of double-layer ferroconcrete constructions showed high fire resistant properties of the developed cement fibre vermiculite concrete fire resistant composites. The algorithm for calculating the fire resistance of multi-layered building constructions with finite-difference implicit scheme for solving the heat conduction problem and the sweep method, providing reasonable agreement with experimental data is offered.