Installing wood stripping under a tin roof.
Steel roof purlins spacing.
An engineer will use a load chart in order to determine the spacing between metal purlins.
Engineered purlin metal mart offers a complete line of engineered purlin material.
The purpose of purlins.
Tin roofing also known as metal roofing is considered more durable than composition or wood shingles.
The building was built 24 on center.
The wider the roofing panels the greater spacing distance you should put.
Once the purlin spacing is determined then the metal roofing panels are typically attached to every line of purlins.
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.
The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed.
Metal building roof purlins provide three structural functions.
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.
Secondly purlins tie the rafters together stabilizing and strengthening the structure s rigid framing.
Screw line spacing for metal roofing over metal purlins.
The width of metal panels will determine the rafter spacing.
Also known as sheeting rails purlins create the roofing members of the secondary framing of a steel building.
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 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.
Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load.
The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.
The metal roof purlins spacing must be done correctly within narrow tolerances.
There is a chance of damaging roofing sheets if you are failed to do so.
Do all roofing projects require purlins.
This will depend upon the type of panel that is used and the thickness of the steel.
The roofing is manufactured in panels that.
First the purlins support the roof.
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.
