This article discusses, for mainly stone monuments, the causes of deterioration, both natural and man made (e.g. weathering and vegetation such as moss or acid rain from vehicle emissions) and some solutions (cleaning with high pressure steam and chemical products, acidic and basic ph balanced), and the coating after cleaning of the objects (silicon based substances - plastics) as a means of preventing/limiting future changes. The article also contains information on the Doerner Institute's research to more concretely determine cause/effect relationships in order to reduce or eliminate the deterioration of objects. Regular maintenance is highly recommended.