Roof Slope Ratio Chart

If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks.

Roof slope ratio chart.

Valley hip factor. Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials. A ratio of 1 1 62 is known as the golden ratio and therefore the vast majority of roof pitch in degrees charts you see will be working to this ratio at the very least. Calculate the rafter length substituting these values into the following formula.

Some sources consider low slope to include 3 12 pitch roofs. Let s say it is equal to 1 5 m. Measure the rise of your roof. Slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run.

Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m. Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. Calculate the roof pitch as the proportion of rise and run.

Download the slope chart pdf. Low slope roofs are from 0 to 3 12 in pitch.