Fireproofing is a general term for a number of methods used to decrease the hazard of fire. The term may refer to building materials or layouts that contribute toward making a building resistant to fire. Fireproofing also means the treatment of ordinarily inflammable materials, such as wood or fabric, with chemicals that make them fire-resistant.
Since it is impossible for a building to be completely fireproof, fire preventive agencies prefer the term fire-resistive to describe buildings most resistant to fire. In such buildings, structural members, walls, partitions, and stairways are made of noncombustible material, such as concrete. Steel members, which are noncombustible but which may buckle at high temperatures, are insulated by a thick covering of asbestos cement or similar material. In addition, to prevent the spread of any fire that might start, large floor areas are broken up by fireproof partitions and fire doors, and rooms containing inflammable materials are enclosed by heavy walls. Stairwells are heavily protected to offer a means of escape.
Older buildings and buildings of wood can be made fire-resistant to some extent by the use of nonflammable materials such as rock wool or fiber glass insulation and asbestos shingles, ceiling tiles, and wallboards. Wood beams for buildings are made fire-resistant by impregnating them with a solution of ammonium salts. Wooden members can also be protected with paint containing chemicals that form a fire-suffocating gas when heated and other chemicals that form a protective crust on the paint.
Additional fireproofing is applied in buildings where dangerous materials are in use, as in industrial plants, and also in buildings where a fire would be particularly disastrous, as in hospitals, schools, and theaters. Draperies and other cloth hangings in such areas are periodically treated with a solution of ammonium salts to make them flameproof. The clothing worn in industrial plants and clothing and bed linens in hospitals are similarly flameproofed at each laundering. In schools, wooden accessories such as desks and bookcases are often flameproofed. Stage scenery is covered with non flammable casein-based paint. Paper decorations, artificial plants, and Christmas trees are also flameproofed to reduce the hazard of fire.