A truss is a structure with straight pieces forming triangles to support a load. The members of the triangles are placed under tension and compression but do not bend. Roof trusses are characterised by an economic use of construction materials (timber, steel). Composed of individual lightweight pieces, a truss can also provide considerable advantage in transport and assembly as compared to conventional roof structures. On the other hand, trusses are more labour-intensive and require connection devices. However, if a greater number of identical trusses can be manufactured, then considerable economies of scale can be achieved.