Required Purlin Spacing For Corrugated Roofing

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.

Required purlin spacing for corrugated roofing.

The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. Corrugated sheet roofing material is widely available and easy to use. The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot. For the greca profile 900mm first and last and 1200mm for the intermediates.

Span tables allow for a maximum 600mm overhang. However sometimes corrugated sheets are 39 wide instead of 37 wide. All dimensions on tables are in millimetres. 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.

There will be four screws per screw line placed in the high of the corrugated panel. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap. The following date is based upon uniform loading of corrugated panels fastened as recommended and with a safety factor of 2 5. In heavy snow areas 500 series or greater panels are recommended and closer spacing of purlins should be considered.

It often depends on the wideness thickness and the types of roofing materials the climate it has to withstand and many other factors. The screws are spaced out so that every third corrugation has a screw. Maximum purlin spacing ro. The standard of lower pitch actually ranges between 1 12 to 5 12.

For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. We do recommend it however. Purlin spacing should suit the end laps required for the size of sheet to be used. Corrugations should run in a straight line between the highest and lowest points and at a right angle to the purlins the intermediate supports.

The diagram above is a typical 37 wide panel and the spacing works out perfectly. Minimum pitch for corrugated metal roof. The overlaps ends and sides depends upon the sloop of the roof see below. Span tables are to be read in conjunction with colorbeam design notes technical specifications and working with colorbeam.