wall

Any of various upright constructions used to divide or enclose a room or building. In traditional masonry construction, bearing walls supported the weight of floors and roofs, but modern steel and reinforced-concrete frames, as well as heavy timber and other skeletal structures, require exterior walls only for shelter. Some urban buildings dispense with walls on the ground floor, extending outdoor plazas under the building and permitting easier access to elevators, escalators, and stairs. In masonry construction, all types of floors and roofs except domes are most easily supported on straight, parallel walls. Nonbearing walls, used when loads are carried by girders, beams, or other members, can be either curtain walls or infill of brick, block, or other material. See also cavity wall, retaining wall, shear wall.