Steel Roof Purlin Spacing

Dead load will be the actual weight of the roof steel and the roof purlins.

Steel roof purlin spacing.

Do all roofing projects require purlins. The building was built 24 on center. There is a chance of damaging roofing sheets if you are failed to do so. 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.

The wider the roofing panels the greater spacing distance you should put. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. This will depend upon the type of panel that is used and the thickness of the steel. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top.

An engineer will use a load chart in order to determine the spacing between metal purlins. Once the purlin spacing is determined then the metal roofing panels are typically attached to every line of purlins. First the purlins support the roof. The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed.

Available in cee or zee shape red oxide primed or galvanized 16 14 or 12 gauge sizes from 4 up to 12 flange widths of 1 1 2 up to 4 cut to your specified lengths hole punching available load tables available for all material. 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. 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. 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 purlins. However the screw placement diagrams commonly are based on the on center spacing center to center of the purlin rather than the gap between purlins to determine the length and spacing of the screws needed to prevent wind blowoff for various design wind speeds so pay close attention to that difference. Screw line spacing for metal roofing over metal purlins. Also known as sheeting rails purlins create the roofing members of the secondary framing of a steel building.

The width of metal panels will determine the rafter spacing. The metal roof purlins spacing must be done correctly within narrow tolerances. Purlins are 2 by 4 feet and are installed much like metal roofing. They give added support to the roof and also provide a nailing surface for the end panels and drip edge.

Metal roof purlins are installed horizontally under metal roofs. Engineered purlin metal mart offers a complete line of engineered purlin material. Metal building roof purlins provide three structural functions.