Pre notch rafters to compensate for slope.
Minimum pitch corrugated plastic roof.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
Courtesy the kemlite company.
The corrugated metal roof minimum slope is 5 degrees.
Just like other metal roofs the minimum pitch for a corrugated metal roof largely depends on the profile of the roof.
4 attach rafters to header and crossbeam with 1 screws and nails.
The pitch is measured in inches of vertical rise per foot of horizontal run and the 5v crimp profile shown above requires a minimum slope of three in twelve or 3 12 3 inches vertically per 12 inches horizontally.
It is the recommended slope as there is no guarantee if you opt for flatter pitch than this.
Corrugated roofing is a great material on traditional pitched roofs but it has severe limitations when the pitch gets below 5 degrees.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
Corrugated metal roofing has the same minimum pitch.
In most occasions a pitch of three in twelve is preferred but this should also take into consideration the manufacturer s recommendations as well the unique condition of the corrugated metal roof.
Allow a 1 minimum pitch per foot for adequate drainage.