Owing to their ease of manufacture and relatively low weight, roof trusses are widely used in construction of industrial facilities. They can be indispensable to cover large building bays without intermediate supports.
Currently, trusses with chords and diagonal elements made from twin angles, as well as trusses made from hollow sections (or, less frequently, round pipes) are the most common. For large spans of buildings, hot-rolled channels or I-beams can be used as chords.
In terms of their plane geometry, trusses are divided into parallel-chord, single-pitch, duo-pitch, and arch trusses.
In terms of their purpose in the structure of the building, trusses are divided into principal and secondary trusses. Secondary trusses are used to connect supporting columns and, in turn, act as a base for principal trusses.
The most commonly, truss elements are connected by semi-automatic or manual arc welding now.