How Far Apart Rafters For Metal Roof

For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet.

How far apart rafters for metal roof.

Wider panels allow for greater spacing between rafters. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot. To determine how far apart to set rafters measure the width of the metal panel and then the width of the first hill and valley of the panel. For roofs that will experience heavy snow or wind and will span the same distance use 2 6 rafters.

Other relevant factors include the type of wood being used for the rafters the size of the rafters and the load that the rafters need to support. A metal roof must also allow for some overlap on each side of the panels which will reduce the effective width of the panel. This translates to seven rows of strips 20 feet long spaced two feet apart or 140 lineal feet of. Repeat the process for your other rafters.

All roof rafters should be identical so follow the same steps to measure the plumb cut tail cut and birdsmouth cut. Depending on the size of your structure you will need to cut several or many more. If you have a simple gable shed roof then using 2 4 rafters makes more sense unless you have a very large shed. The spacing between rafters in a given building is part of the engineering calculations that determine the required structure of the roof.

In this example the section of roof is 20 feet wide and 14 feet from the fascia to the peak.