Minimum Pitch For Corrugated Plastic Roof

The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.

Minimum pitch for corrugated plastic roof.

The cladding should be supported at maximum centres as specified by the manufacturer and fixings should be a minimum of 50mm from sheet ends. 3 pre notch rafters to compensate for allow a 1 minimum pitch per foot for adequate drainage. 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. The roof should have a pitch of at least one inch per foot to allow water to drain properly.

If your roof has a shallower pitch you may need to use additional weatherproofing measures. Allow 7 4 from floor to bottom of front header for best ventilation. 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. For a secure and attractive finish you should use molding strips on top of the rafters.

Anything above that will require you to put out higher cost because they are already considered as higher pitch. However you can only use this pitch with built up roofing or specialized synthetic roofing. Corrugated metal roofing has the same minimum pitch. The standard of lower pitch actually ranges between 1 12 to 5 12.

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 is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.