However you can only use this pitch with built up roofing or specialized synthetic roofing.
Roof pitch for lean to.
Regular asphalt shingles that are rated for 4 in 12 roof slopes can be installed on lower slope roofs by simply installing a waterproof membrane under them.
You can also calculate roof pitch even without using a roof slope calculator.
Solutions for lean to sheds both the asphalt shingles and metal roofs can be installed on a low slope lean to shed roof if the proper product is used and it is installed properly.
A low pitched roof is anything that is any roof with a pitch of 3 12 or less.
They have a pitch ranging from 4 12 to 9 12.
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.
High pitched roofs often need extra fasteners and their pitch can be as high as 21 12.
Many roofing shingles do not allow applications onto roofs at this pitch.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.