walls
The walls of a building are the vertical portions that enclose the building or subdivide it into the rooms: the subdividing walls are usually called partitions. Exterior walls are constructed of brick, stone, hollow clay tile, concrete blocks or combinations of these materials laid up with mortar joints. Exterior walls are also made of reinforced concrete. Modern steel and reinforced-concrete frames require exterior walls only for shelter. As the wall rests or hangs upon members of the frame it becomes a screen and may be treated in any durable, weather-resisting material. There are two types of a wall.1) Load bearing wall which supports the weight of floors and roofs.
2) Nonbearing wall which supports its own weight. The load-bearing wall of masonry is thickened in proportion to the forces which it must resist: its own load, the load of floors, roofs, persons etc... And the lateral forces of arches, vaults, wind, etc... That may cause it to crack. Its thickness can often be reduced at the top, because loads accumulate towards the base; walls that must resist lateral forces are thickened along the whole length or at some points where the force is concentrated. Doors and windows weaken the resistance of the wall and direct the forces above them to the parts on any side, which must be thickened in proportion to the width of the opening. In multistory buildings windows must be placed one above the other so as to leave continuous vertical masses of wall between them to transfer loads directly to the ground. The number of openings that can be used depends on the strength of the masonry and the stresses in the wall. Walls in light, wood-framed structures and in reinforced-concrete Construction may also have a bearing function. The placement of walls is determined by the type of support for floors and roofs. The most usual support is the beam which must be jointed to wall at both ends; so its maximum allowable length establishes the distance between bearing walls. All floors and coverings are easily supported on straight, parallel walls. The nonbearing wall is constructed where loads are carried by other members as in heavy timber and other skeleton structures. Traditional materials are often used in the construction of these walls, but light walls of glass, plastics, metal alloys, wood products etc.... can be very effective too. Nonbearing walls may be thinner than bearing walls.
