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After we bought our 1930s bungalow, I discovered that the flooring onthe stairs and entry, which had been carpeted, is magnesite. In addition to the nail holes from the carpet, it has been painted and has some minor cracks. Is it restorable?
Jeff Keen
Westwood, California

Frank Lloyd Wright used this material, which is magnesium oxychloride cement, colorant (usually tan, brown, green, or red), and a filler, such as sawdust or wood chips, in several of his houses and other buildings in the first decade of the 20th century, but it probably saw its greatest popularity between the 1930s and Õ50s.

ItÕs amazingly durableÑnoncombustible, resistant to oils and grease, and more resilient under foot than regular cement because of the woody filler. It can be finished with tung oil or wax. Wear gives it a patina similar to well-worn leather. It can also be sloped for drainage and has been used extensively in California for outdoor decking.

Considered economical in WrightÕs day it is now rather expensive to have installed new, and it is becoming increasingly difficult to find craftsmen with the skills and patience required to make repairs. The material is troweled on top of wood flooring and wire mesh (sometimes separated with felt) to a thickness of only 1/2ý to 3/4ý. Setting time is crucial to magnesite repair because the material is easily Òtrowel burned.Ó Ambient conditions, such as humidity, can affect setting time.

Matching the stain can be a challenge, as can finding aggregate small enough to fill small nail holes. To strip paint off your flooring, begin with a gentle approach. In a couple of test spots, try buffing with detergent, being careful not to get the magnesite too wet. For several layers you may need a strong chemical stripper, but be sure to follow safety warnings on the label. Magnesite flooring the age of yoursÑjust like linoleum of about the same ageÑoften contains some asbestos, so donÕt try to sand or paint any flooring that is chipped or crushedÑthis can release asbestos fibers and should be handled by contractors licensed to do such work. New material for installing and repairing magnesite contains no asbestos. Although magnesite fell out of popularity in homes and public buildings after World War II, Adams notes that itÕs still popular on ships and military applications for its insulative and nonconductive properties. One company that sells magnesite repair products and may be able to help you find professional help is Hill Brothers Chemical Company in Orange, California. For more information visit www.hillbrothers.com.