Wall

A wall is a vertical structure, usually solid, that defines and sometimes protects an area. Most commonly, a wall delineates a building and supports its superstructure, separates space in buildings into rooms, or protects or delineates a space in the open air. There are three principal types of structural walls: building walls, exterior boundary walls, and retaining walls. The two types of walls are load-bearing, which supports the weight of floors and roofs, and non-bearing wall, which at most supports its own weight. Load-bearing wall. The load-bearing wall of masonry is thickened in proportion to the forces it has to resist: its own load, the loadof floors, roofs, persons, etc., and the lateral forces of arches, vaults, wind, etc., that may cause it to crack or buckle.
 * Wall**

 For example doors and windows weaken the resistance of the wall and divert the forces about them to the parts on either side, which must be thickened in proportion to the width of the opening. In multistory buildings, windows -unless they are very small- must be placed one above the other so as to leave uninterrupted vertical masses of wall between them to transfer loads directly to the ground.

Excluding the independent garden variety, the non-bearing wall appears only where loads are carried by other members, as in heavy timber and other skeletal structures. Modern steel and reinforced-concrete frames require exterior walls only for shelter and sometimes dispense with them on the ground floor to permit easier access. Since the wall rests or hangs upon members of the frame, it becomes a curtain screen; and admitstreatment in any durable, weather-resisting material. Traditional materials are often used, but light walls of glass, plastic, metal alloys, wood products, etc., can be equally efficient.