Purlin Spacing For Corrugated Metal Roofing

Be sure the larger edge is laid so that the small edge of the next panel will overlap it.

Purlin spacing for corrugated metal roofing.

For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap. Corrugated metal panels often called tin because in the past such panels were sometimes made of tin are typically steel or aluminum sheets that are used as a roofing material. There will be four screws per screw line placed in the high of the corrugated panel. Purlin spacing should suit the end laps required for the size of sheet to be used.

All purlin joints must be supported by a rafter. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot. Z purlins are connected to the rafters using cleats.

Kiln dried softwood is recommended for purlins or decking pine fir hemlock and spruce. However sometimes corrugated sheets are 39 wide instead of 37 wide. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. Purlin spacing is dependent on profile of the metal and gauge plus snow and wind load plus what the rafters are designed to carry.

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. Purlin spacing for metal roofing. The overlaps ends and sides depends upon the sloop of the roof see below. Pullout values decrease if the fasteners protrude completely through the purlins.

When using purlins fabral recommends a maximum spacing of 24 on center note that 5v requires solid decking. The screws are spaced out so that every third corrugation has a screw. 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. 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.

Fyi we run purlins on 3 5 feet on center depending on size of purlin. These panels can cost more to install that a traditional roof but in the long run are often a better value. Do all roofing projects require purlins. Without a set of blueprints with a pe s seal you have no option but to follow the inspectors gig.

Install the roofing screws vertically along each rib in the panel. Minimum recommended purlin size is 4 x 2 50mm x 100mm in timber or z140mm x 1 6mm in steel. Corrugations should run in a straight line between the highest and lowest points and at a right angle to the purlins the intermediate supports. Corrugated sheet roofing material is widely available and easy to use.

We do recommend it however.