Summary

Cast stone-a mixture of water, sand, coarse aggregate, and cementing agents--has proven over time to be an attractive and durable building material, when properly manufactured. It gained popularity in the 1860s and, by the early decades of the 20th century, became widely accepted as an economical substitute for natural stone. Unfortunately, much historic cast stone is unnecessarily replaced when it could easily be repaired and preserved in situ, or left untreated. Appropriate repair of damaged units can extend the life of any cast stone installation. Because of the necessity of matching both matrix color and aggregate size and ratio, conservation projects which involve repair or replication of cast stone should allow adequate lead time for the assembly of materials and the preparation of test samples. Understanding which conditions require repair, which warrant replacement, and which should be accepted as normal weathering is key to selecting the most appropriate approach to the protection and care of historic cast stone.

Selected Reading

Childe, H.L. Manufacture and Uses of Concrete Products and Cast Stone, London: Concrete Publications Limited, 1930.

Jester, Thomas C., ed., Twentieth Century Building Materials, New York, NY: McGraw-Hill, 1995.

Precast/Prestressed Concrete Institute, Architectural Precast Concrete, 2nd ed., Chicago, Illinois: Precast/Prestressed Concrete Institute, 1989.

Whipple, Harvey, Concrete Stone Manufacture, Detroit: Concrete-Cement Age Publishing Company, 1918.