Steel Roof Purlin Spacing

This will depend upon the type of panel that is used and the thickness of the steel.

Steel roof purlin spacing.

The width of metal panels will determine the rafter spacing. The cos of the purlin spacing is because the load on the purlins is vertical and the purlin spacing is with the run of the roof. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. Also known as sheeting rails purlins create the roofing members of the secondary framing of a steel building.

Secondly purlins tie the rafters together stabilizing and strengthening the structure s rigid framing. For sake of discussion we will assume a minimal roof snow load of 20 psf pounds per square foot and a 4 12 roof slope. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. There is a chance of damaging roofing sheets if you are failed to do so.

Purlins are 2 by 4 feet and are installed much like metal roofing. The wider the roofing panels the greater spacing distance you should put. Do all roofing projects require purlins. Screw line spacing for metal roofing over metal purlins.

Metal building roof purlins provide three structural functions. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. The purpose of purlins. We do recommend it however.

Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load. Once the purlin spacing is determined then the metal roofing panels are typically attached to every line of purlins. Purlin spacing for metal roofing the country inspector upon approving the plans seems to have written in per manufacturers specs regarding 2x4 purlins on 16 centers. The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed.

The building was built 24 on center. Purlins are non pressure treated 1 x 4 x 12 lumber that is installed on to the roof in a specific layout pattern and screw pattern. An engineer will use a load chart in order to determine the spacing between metal purlins. First the purlins support the roof.

Engineered purlin metal mart offers a complete line of engineered purlin material. Dead load will be the actual weight of the roof steel and the roof purlins. Metal roof purlins are installed horizontally under metal roofs.