The results from the experimental research are presented in the abstract. The experimental research involved utilization of the sludge from the mine water treatment plant of Coal Quarry ČSA/Czechoslovak Army/ (hereinafter “ČSA”) and Coal Quarry Jana Švermy (hereinafter “JŠ”) in the segment of thermal insulation mortars. The mine water treatment is described below including chemical and mineralogical sludge composition as the additional component of the binding material in the polyurethane thermal insulation mortars. Furthermore the composition of experimental mixtures of the thermal insulation polyurethane mortar is presented in the work and its physical-mechanical properties. The monitored elements included the strength characteristics, heat conductivity coefficient λ, and water vapour diffusion coefficient μ.