Stone Conservation on Buildings and Monuments

Abstract

The rapid, visible decay of stone in urban areas has made it necessary to protect stone surfaces from premature decay; the attempt is to halt the natural process of stone decay but we can merely slow down nature’s continuous gnawing. Protective commercial chemicals have been applied since the 17 th century. The heterogeneity of stone, however, does not permit a generalized panacea; the number of failures in stone preservation is greater than cures. In the early days of stone treatment, the access of surface water was prevented by the application of linseed oil and hot waxes. Total sealing rarely solved the problem, as the actual travel routes for moisture within the monument or from the ground were not yet understood. Undesirable stains, efflorescence and accelerated flaking were the result. Today, the great variety of chemicals consists of sealing paints and varnishes, and silicones, resins and other compounds designed to achieve efficient penetration.