Required Purlin Spacing For Corrugated Roofing

All dimensions on tables are in millimetres.

Required purlin spacing for corrugated roofing.

We do recommend it however. Purlin spacing should suit the end laps required for the size of sheet to be used. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. 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.

Corrugated sheet roofing material is widely available and easy to use. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap. Anything above that will require you to put out higher cost because they are already considered as higher pitch. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.

The standard of lower pitch actually ranges between 1 12 to 5 12. Corrugations should run in a straight line between the highest and lowest points and at a right angle to the purlins the intermediate supports. In heavy snow areas 500 series or greater panels are recommended and closer spacing of purlins should be considered. However sometimes corrugated sheets are 39 wide instead of 37 wide.

Maximum purlin spacing ro. Suntuf is supported on the structure via purlins these are the bearers that run left to right along the width of the roof the maximum purlin spacing for the corrugated profile is 800mm centres on the first and last purlins and 1 meter centres for the intermediate purlins. The following date is based upon uniform loading of corrugated panels fastened as recommended and with a safety factor of 2 5. Maximum rafter spacing or purlin span p.

Minimum pitch for corrugated metal roof. The screws are spaced out so that every third corrugation has a screw. The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot. The overlaps ends and sides depends upon the sloop of the roof see below.

The diagram above is a typical 37 wide panel and the spacing works out perfectly. Span tables allow for a maximum 600mm overhang. Do all roofing projects require purlins. For the greca profile 900mm first and last and 1200mm for the intermediates.