Purlin Size For Metal Roofing

Net variation for combned dimension.

Purlin size for metal roofing.

The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap. We do recommend it however.

Do all roofing projects require purlins. 22 24 26 29. For 2x4s purlins the posts are spaced in 4 feet distance. 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 typical spacing standards for residential and commercial buildings are about 1 to 2 foot. In many cases post frames lack structural sheathing so the roof panels will need to span between the supporting purlins or trusses. The standard of purlin length will vary anywhere between 100 to 300 mm while the thickness will vary anywhere between 1 to 3 mm. Available in red oxide or galvanized cee purlins are cut to the nearest 1 8.

Lighter gauge panels like 22 24 and 26 gauge sheeting will remain more structurally sound for years to come. If you want to know how to support roof purlins they are usually supported by 2 4 or 2 6 struts or posts.