Measuring Roof Pitch Angle

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.

Measuring roof pitch angle.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. A 12 12 pitch roof has a pitch angle of 45. Take a measurement of 12 inches using a level. This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees.

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. Check the surface of the. 48 10 4 8. Now divide the rise by the multiplier to get the pitch eg.

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. Divide the height of your roof by the width not the full width if you ve measured the full width wall to wall divide. Pitch is the incline of the roof represented as the ratio of rise to the span twice the run. Rafter height width from pythagoras remember that at school so.

To convert between american roofing ratios and pitch degrees follow these steps. The pitch of this roof is 4 8 12. The calculator above can handle much of this math. If you want to know how to find the pitch of a roof then start with a calculator.

Find the inverse tangent of the pitch to find the angle in degrees. 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. Take the measurement of the vertical. It always makes sense to the standard roof pitch angle spot on as the benefits of doing so are quite obvious.

Position your level against the roof until the bubble of the vial sits between two lines. 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. Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level. Take your pitch percent and press shift maybe 2nd function on your calculator then press tan and.

Before taking any measurements you must first confirm that it s safe to walk on your roof. Divide the first part of the ratio by 12 to work out the pitch.