A truss is formed with an assembly of inflexible and elastic members  connected as the triangles so they can perform like a beam. The tensile stress of mild steel is secure for working and approximately 20 times as compared to structural timber. Because of these reasons the steel trusses are considered as cost-effective, particularly for largest extents. 
There are more benefits of the steel roof truss compared with the timber truss: steel trusses last longer compared to timber trusses; Steel sections that develop the truss are lightweight and are constructed in any preferred pattern to match the requirement of any architectural work; as it is made with steel, the material is not damaged by white ants or other insects…and more in the link bellow.
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