Roof Trusses:

For covering large industrial or residential areas, to protect them against rain, sun, dust or other natural vagaries, we require roofing. The material used for roofing are called roof covering that might range from tiles, corrugated steel and asbestos sheets to light FRP covers and tarpaulins. Therefore, these materials are not structurally strong sufficient to support themselves and need to be supported by steel or concrete structures. Beams are a few of the more general structural elements to support roofs. But while the area and the span also to be covered become too huge, beams also become too heavy and uneconomical as structural members. The next most common type of roof supporting structures is truss elements, called roof trusses. Roof trusses are composed of tension and compression members joined together by welding or riveting. Purlins are the members which carry the roof cladding directly and are subjected to bending as in. The shape of the roof trusses are determined largely by the area and space to be covered, the use under which the covered premises is put and the type of roof cover used. The truss could be visualised as beam along with inclined flanges and open web.