First measure 12 inches from one end of the level and make a mark.
Measuring roof pitch angle.
Divide the height of your roof by the width not the full width if you ve measured the full width wall to wall divide.
The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7.
Roof pitch and corresponding angles.
Since pitch is the rise over a 12 inch run divide the run by 12 to get the multiplier in this case 120 12 10.
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.
A 12 12 pitch roof has a pitch angle of 45.
The pitch of this roof is 4 8 12.
Take the measurement of the vertical.
Pitch is the incline of the roof represented as the ratio of rise to the span twice the run.
This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees.
With the help of these roof pitch degree calculator programs you can make sure that your home is nice and balanced.
Divide the first part of the ratio by 12 to work out the pitch.
On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length.
To convert between american roofing ratios and pitch degrees follow these steps.
Take a measurement of 12 inches using a level.
It always makes sense to the standard roof pitch angle spot on as the benefits of doing so are quite obvious.
How to measure roof pitch to measure the roof pitch you ll need an 18 or 24 inch level a tape measure and a pencil.
48 10 4 8.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
Before taking any measurements you must first confirm that it s safe to walk on your roof.
Now divide the rise by the multiplier to get the pitch eg.
Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level.
Position your level against the roof until the bubble of the vial sits between two lines.
The calculator above can handle much of this math.
Take your pitch percent and press shift maybe 2nd function on your calculator then press tan and.
Rafter height width from pythagoras remember that at school so.