Purlins Shed Roof

The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed.

Purlins shed roof.

The shape of cee purlins does not allow end lapping they are butted together. These structural supports run perpendicular across the rafter beams. 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. Purlins are 2 by 4 feet and are installed much like metal roofing.

Cee purlins are secondary steel framing members most commonly used as roof purlins wall girts and header jamb and sill for windows and doors on metal buildings. Welded together they can be used as columns braces and ties. Metal roof purlins are installed horizontally under metal roofs. This design is a lot stronger and more robust way of making a steel shed.

Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. Purlins are an important component in a pre engineered steel structural kit. The purpose of purlins.

Also known as sheeting rails purlins create the roofing members of the secondary framing of a steel building. 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.