Purlins Metal Roof Spacing

The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.

Purlins metal roof spacing.

For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load. Purlins are dimensional lumber that are fastened to the top chord of trusses connecting them together for bracing purposes. 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.

By the standard the most used placement of purlin span for metal roof is five foot intervals. 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. Purlins are 2 by 4 feet and are installed much like metal roofing.

Spacing for purlins on a standard load most designs call for purlin placement at five foot intervals. For 2x4s purlins the posts are spaced in 4 feet distance. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot. Installation of pole barn purlins.

The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. We do recommend it however. Screw line spacing for metal roofing over metal purlins.

For 2x6s purlins the posts are spaced in 6 feet distance. This will depend upon the type of panel that is used and the thickness of the steel. Once the purlin spacing is determined then the metal roofing panels are typically attached to every line of purlins. The spacing of purlins on roofs and girts on wall is usually 4 to 6 ft.

Numbers 20 and 22 u s. If the space between posts is greater than 8 feet then brace is needed to avoid buckling. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. Standard gage are generally used for roofing.

Metal roof purlins are installed horizontally under metal roofs. The heavier the expected load is the shorter the distance between the purlins. However engineering determines the optimal spacing between the purlins. 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.