Metal Building Roof Purlin Spacing

When framing the roof the spacing for roof trusses should not exceed 24 inches 61 cm and purlins should not exceed 36 inches 91 cm apart.

Metal building roof purlin spacing.

You can use both types of corrugated roofing together creating panels that will allow light to come through as with a clear or white fiberglass corrugated panel known as a skylight. Do all roofing projects require purlins. Purlin spacing is dependent on profile of the metal and gauge plus snow and wind load plus what the rafters are designed to carry. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot.

Without a set of blueprints with a pe s seal you have no option but to follow the inspectors gig. Purlins are dimensional lumber that are fastened to the top chord of trusses connecting them together for bracing purposes. The support system for the roof is comprised of ridgepole and rafters or purlins. The use of purlins as opposed to closely spaced rafters is common in pre engineered metal building systems and both the ancient post and beam and newer pole building timber frame construction.

For 2x6s purlins the posts are spaced in 6 feet distance. If your design or local building codes demand extreme spans or snow loads taller purlins may be required. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed.

Once the purlin spacing is determined then the metal roofing panels are typically attached to every line of purlins. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. 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. Net variation for combned dimension.

We do recommend it however. By the standard the most used placement of purlin span for metal roof is five foot intervals. Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load. If the space between posts is greater than 8 feet then brace is needed to avoid buckling.

An engineer will use a load chart in order to determine the spacing between metal purlins. Fyi we run purlins on 3 5 feet on center depending on size of purlin. Purlin spacing for metal roofing. Twist is measured with the zee laying on a flat surface under its own weight.

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. Installation of pole barn purlins. For 2x4s purlins the posts are spaced in 4 feet distance. Rhino metal building purlins and options traditionally rhino steel buildings use 8 to 10 primed red iron c purlins and z purlins.