For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally.
Formula roof pitch.
Formula roof slope is also called as roof pitch.
First measure 12 inches from one end of the level and make a mark.
Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level.
The slope is the same as the pitch.
Image 1 12 to 12 12 roof pitch 7 12 pitch.
In the roofing trade the go to term is pitch and it is expressed in terms of 12 inches so the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally.
In the uk the typical house has a pitch between 40 50 although 45 should be avoided.
Divide the slope by two to get the pitch.
Roof pitch varies depending on culture climate style and available materials.
A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch.
In civil engineering the slope is the numerical measure of the steepness of a roof.
In the usa the range of standard pitches is anywhere between 4 12 and 9 12.
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.
Roof pitch calculator is determined by the number of inches it rises vertically for every 12 inches it extends horizontally.
The 7 means that the roof rises 7 for every 12 it runs.
Tan a rise y1 run x our sketch above shows how we calculate the roof rise per horizontal foot 12 inches of run when we are given the roof slope in degrees or as the roof pitch or angle expressed in degrees the purple sloped line is the sloping roof surface.
By slope angle formula steepness can be obtained by dividing vertical rise by horizontal span.
Here s an easy safe way to determine the pitch from inside your attic.
Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.
As aforementioned there is no standard pitch of a roof.
There is no standard universal roof pitch.
Pitch angle incline slope they all can be used to refer to the steepness of a roof.
For a roof with the ridge above one wall the span is the same as the run.
To measure the roof pitch you ll need an 18 or 24 inch level a tape measure and a pencil.