Pitch Roof Slope Angle

First convert the pitch to a slope.

Pitch roof slope angle.

Rise run rise run slope. A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. A 12 12 pitch roof has a pitch angle of 45.

Some sources consider low slope to include 3 12 pitch roofs. A 4 12 pitch is around 18 5 degrees but not exactly. Low slope roofs are from 0 to 3 12 in 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.

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. Often you express roof pitch as the ratio between the rise and the run in the form of x 12. Roof pitch is a term describing how steep or flat your roof slope is. Roof pitch angle and slope factor charts.

Roof pitch refers to the slope which the rafter creates. To find the angle of a roof in degrees convert the pitch to a slope then convert to degrees by finding the arc tangent of the slope. Find the inverse tangent of the pitch to find the angle in degrees. You can also divide the rise over run multiply by 100 and get a percentage.

The combination of two numbers are used to display or show the roof pitch. To convert between american roofing ratios and pitch degrees follow these steps. If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks. Thus a 4 12 pitch would be a 33 slope.

See low slope roofing. Divide the first part of the ratio by 12 to work out the pitch. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.