Lime plaster

Description

A type of plaster composed of calcium oxide (lime). Lime plaster has been used since antiquity. It is prepared by heating limestone to remove carbon dioxide and convert it to anhydrous calcium oxide (quicklime). When quicklime is mixed with water, it converts to calcium hydroxide (slaked lime). Slaked lime hardens in two steps. First the water evaporates, then atmospheric carbon dioxide reacts with the calcium hydrate to form calcium carbonate. The final result is a mass of calcium carbonate crystals. Often aggregates or binders are added to increase the strength and decrease porosity. Lime plasters were used for wall coverings, frescos and wall decoration. See also lime mortar.

Synonyms and Related Terms

lime; quicklime; slaked lime

Hazards and Safety

Susceptible to damage from water and pollutants.

Additional Information

E.Sayre, "Deterioration and Restoration of Plaster, Concrete and Mortar" in Preservation and Conservation: Principles and Practice, S.Timmons (ed.), Preservation Press, Washington DC, 1976.

Authority

• R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966

• Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996

• Encyclopedia Britannica, http://www.britannica.com Comment: "Plaster." Encyclopædia Britannica. 2004. Encyclopædia Britannica Premium Service. 14 July 2004 .