These effects can largely be eliminated by the pre-treatment of surfaces using Polysil. Polysil-TG500 is an aqueous formulation of silicic acid compounds which chemically react with the substrate to produce a “silicification effect”. Silica gel is formed within the capillaries reducing pore sizes, consolidating and strengthening the treated material. The hydrophobic effect of Polysil-TG500 largely eliminates the leaching of mineral such as free lime and salts.