Express roof pitch as the ratio of the amount of the vertical rise of a roof or rise over the corresponding horizontal distance or run you write the pitch assuming a run of 12 inches thus the ratio would describe how much a roof rises for each foot of the run.
How much pitch for a patio roof.
The recommended slope is 1 4 inch per foot but it can be anywhere from 1 8 inch to 3 8 inch per foot depending on other factors.
Most roof s have a pitch in the 4 12 to 9 12 range.
If the pitch of your roof is 6 inches per 2 inches the angle would be 26 5 degrees.
We included a roof pitch chart below the 7 12 example image and the calculator below that.
You could also opt for a pvc flat roofing membrane.
This meant the patio cover could start at the edge of the house s roof at a height of eight feet and slope down to seven feet leaving a clearance of more than six and a half feet between the lowest part of the frame s headers and the ground at its outer edge.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
A roof that slopes 12 inches for every 12 inches would have a 45 degree angle.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
So you would need to pick the right option as most regular standing seam metal roofs will require a roof pitch of 2 12 or even 3 12 at a minimum.
Such a small pitch can only work with built up roofing or specialized synthetic roofing.
You need to remove any vegetation soft soil and rocks before you begin.
For example if the roof rises 4 feet and the span is 16 feet twice the run then the pitch is 4 16 or 1 4.
The table below shows common roof pitches and the equivalent grade degrees and radians for each.
Since most building codes require a pitch of at least one quarter inch per 12 inches you should anticipate that the angle of your roof will be at least 4 degrees.
The rafter member will be longer.
If this isn t practical then perform the same measurement on the underside of the roof.
As aforementioned there is no standard pitch of a roof.
Covered porches that are near trees or in areas with heavy rains should not be covered with a low slope roof.
If you plan to have overhang etc.
A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof.
When you are building a patio from scratch you will have no trouble making sure that it is sloped correctly.