Roof Slope Ratio Chart

Calculate the roof pitch as the proportion of rise and run.

Roof slope ratio chart.

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. 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. Notes to the table above. Let s say it is equal to 1 5 m.

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. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m. Download the slope chart pdf.

Valley hip factor. Measure the rise of your roof. Some sources consider low slope to include 3 12 pitch roofs. Low slope roofs are from 0 to 3 12 in pitch.

Calculate the rafter length substituting these values into the following formula. If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks.