BRICK AND TILE

structural clay products, manufactured as standard units, used in building construction. The brick, first produced in a sun-dried form at least 6,000 years ago and the forerunner of a wide range of structural clay products used today, is a small building unit in the form of a rectangular block, formed from clay or shale or mixtures and burned (fired) in a kiln, or oven, to produce strength, hardness, and heat resistance. The original concept of ancient brickmakers was that the unit should not be larger than what one man could easily handle; today, brick size varies from country to country, and every nation's brickmaking industry produces a range of sizes that may run into the hundreds. The majority of bricks for most construction purposes have dimensions of approximately 5.5 9.5 20 centimetres (21/4 33/4 8 inches). Structural clay tile, also called terra-cotta, is a larger building unit, containing many hollow spaces (cells), and is used mainly as backup for brick facing or for plastered partitions. Structural clay-facing tile is often glazed for use as an exposed finish. Wall and floor tile is a thin material of fireclay with a natural or glazed finish. Quarry tile is a dense pressed fireclay product for floors, patios, and industrial installations in which great resistance to abrasion or acids is required. Fireclay brick is used in incinerators, boilers, industrial and home furnaces, and fireplaces. Sewer pipe is fired and glazed for use in sewage-disposal systems, industrial waste systems, and general drainage. Drain tile is porous, round, and sometimes perforated and is used mainly for agricultural drainage. Roofing tile is made in the form of half-round (Spanish tile) and various flat tiles made to resemble slate or cedar shakes; it is used extensively in the Mediterranean countries. There are also many products made from cement and aggregates that substitute for, and generally perform the same functions as, the structural clay products listed above. These nonclay brick and tile products are described briefly at the end of the article. The main subject of this article, however, is the brick and tile produced from fireclay. Outline of Coverage Fireclay brick and tile are two of the most important products within the field of industrial ceramics. For background information on the nature of ceramic materials, see the articles presented in Industrial Ceramics: Outline of Coverage, particularly the articles on traditional ceramics. For lengthy treatment of the principal application of fireclay brick and tile, see the article building construction. Additional reading Harry C. Plummer, Brick and Tile Engineering, 2nd ed. (1962), is a comprehensive technical publication on brick manufacturing, sizes, design, and uses. Bernd Foerster, Man and Masonry (1960), is a brief pictorial presentation of masonry structures over time as related to the human environment. Technical Notes on Brick Construction (irregular), published by the Brick Institute of America, covers all phases of brick and tile production and use. Historical aspects are examined in two articles in National Geographic Magazine: E.A. Speiser and H.M. Herbert, Ancient Mesopotamia: A Light Did Not Fail, 99(1):41105 (January 1951), on the ancient use of brick with references to brickmaking; and Stuart E. Jones and Winfield Parks, When in Rome . . . , 137(6):741789 (June 1970), illustrating the history of masonry, including construction during Hadrian's reign and the brick dome on the Pantheon.A good introduction to ceramics in general is provided by David W. Richerson, Modern Ceramic Engineering: Properties, Processing, and Use in Design, 2nd ed., rev. and expanded (1992). The processing of traditional ceramics is described in F.H. Norton, Elements of Ceramics, 2nd ed. (1974); James S. Reed, Introduction to the Principles of Ceramic Processing (1988); George Y. Onoda, Jr., and Larry L. Hench, Ceramic Processing Before Firing (1978); and in four sections of Theodore J. Reinhart (ed.), Engineered Materials Handbook, vol. 4, Ceramics and Glasses, ed. by Samuel J. Schneider (1991): Ceramic Powders and Processing, pp. 41122; Forming and Predensification, and Nontraditional Densification Processes, pp. 123241; Firing/Sintering: Densification, pp. 242312; and Final Shaping and Surface Finishing, pp. 313376. James A. Lee Thomas O. Mason The Editors of the Encyclopdia Britannica