Lean To Rafter Spacing For Metal Roof

Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.

Lean to rafter spacing for metal roof.

In other words if there is a 1 1 2 ridge board nailed into the wall and the width of the lean to is 96 then the run will be 94 1 2 96 1 1 2 94 1 2. A metal roof must also allow for some overlap on each side of the panels which will reduce the effective width of the panel. Wider panels allow for greater spacing between rafters. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot.

The same concept holds true for roof trusses. Common spacing for trusses on this type of building is often between 2 and 4 feet but trusses built with advanced designs may allow spacing as great as 8 or 12 feet. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap.

Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. 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. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. I cut rafters out of 2x8s frame this pole barn lean to.

For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. If you ve wondered how to frame a lean to roof off a pole barn this video will show you how i did it.

The run for a lean to shed rafter ending into a wall should account for the ridge board nailed into the wall where the tops of the rafters rest into. It is always better to have a large rafter rather than be concerned with a sagging roof.