Roof Purlin Beam

In architecture structural engineering or building a purlin or historically purline purloyne purling perling is a horizontal beam or bar used for structural support in buildings most commonly in a roof.

Roof purlin beam.

Like the z purlin the c purlin takes its name from its shape. Purlins support the loads from the roof deck or sheathing and are supported by the principal rafters and or the building walls steel beams etc. In the past the majority of roof structures were of wooden construction but over the past 15 to 20 years there has been a vast shift away from wood to metal mainly steel roof construction. With this layout the upper level which is typically framed construction rather than log the ceiling slash roof can use rafters and purlins to add log elements.

Purlins and girts are used longitudinally to support the roof sheeting which they were originally designed for. Available in a variety of sectional properties lengths and sizes. Purlins are supported either by rafters or the walls of the building. In a structural steel shed the main portal frames and roof rafters are made from strong steel sections which are welded together and later bolted together.

This design is a lot stronger and more robust way of making a steel shed.