Masonry and sculptures of the Tein church are mainly made of Pläner limestone. Causes and type of limestone deterioration are described. The limestone elements have been subjected to impregnation with silicone ester and epoxy resin. Five brands of silicone ester are indicated as suitable for impregnation. Used in this particular case was a mixture of methyltrimetofysilane, tetramethoxysilane and solvent. Samples of Pläner limestone were impregnated with the silicone ester mixture and with epoxy resin and then tested. Data about the chemical and physical behavior of the impregnated sample are presented in tables and graphs. The thermodynamics of the system -- limestone, consolidant, temperature, and moisture -- are explained. Silicone esters do not change the mechanical properties of the limestone, but protect it against frost damage. Epoxy resins impart to the stone five times as much sharing stress as is measured in untreated stone. -- AATA