Purlin Spacing For Metal Roof

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

Purlin spacing for metal roof. For 2x4s purlins the posts are spaced in 4 feet distance. Without a set of blueprints with a pe s seal you have no option but to follow the inspectors gig. Purlin spacing for metal roofing.

We do recommend it however. In many cases post frames lack structural sheathing so the roof panels will need to span between the supporting purlins or trusses. Metal roofing gauges can be a complicated topic so we get asked tons of questions by people.

Edit answer for another 15 minute you need to check the installation instructions from the manufacturer depending on whether the purlins firring strips are 1x or 2x material and how wide thickness metal gage of roofing steel or aluminum type of seams design wind and snow loading whether designed to be walked on or not etc i have seen it vary from as little as 4 inches clear gap between firring strips on lightweight aluminum to as much as 4 feet on very heavy gage steel. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap. 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. Screw line spacing for metal roofing over metal purlins. Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load.

Purlin spacing is dependent on profile of the metal and gauge plus snow and wind load plus what the rafters are designed to carry. Here is the formula for calculation of a roof purlin. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot.

Lighter gauge panels like 22 24 and 26 gauge sheeting will remain more structurally sound for years to come. Numbers 20 and 22 u s. Once the purlin spacing is determined then the metal roofing panels are typically attached to every line of purlins.