A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope.
Roof rise slope.
Roof pitch is often expressed as a ratio between rise and run in the form of x 12.
Pitch is thus the ratio of the rise in inches to a 12 inch run and is often expressed using a semicolon for example 6 12.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.
The minimum roof slope for metal roofs is dependent upon the roof profile.
Last updated july 10 2020 the following table shows the roof pitch rise in run equivalents for all roof slopes in degrees from 1 to 72.
Access one of the rafters then take.
To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope.
This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares.
For example a pitch 1 12 means that per every twelve yards of building length the rise will be equal to one yard.
Low slope roofs are from 0 to 3 12 in pitch.
It can be assessed in two ways either as the angle the rafter makes with the horizontal or the proportion between the rise and the run of the roof.
If the rise is 6 inches for every 12 inches of run then the roof slope is 6 in 12 the slope can be expressed numerically as a ratio.
A 3 in 12 roof rises 3 for every 12 of run.
That s the same as a 14 degree slope or a 25 slope.
3 of rise per 12 of run is the same as 1 of rise per 4 of run or 1 4 25.
With regards to metal roofing the profile refers to the shape adopted by the metal sheets when they are bent to form the panels.
While roof slope is typically expressed in rise it can also be expressed in degrees or in percent of slope.
Squaring building lines example 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.
Clearly once we get near 90.
Other than the 45 roof slope which is 12 in 12 none of the standard roof pitches 5 in 12 6 in 12 etc are equal to a whole degree.
Use a level against the underside of the rafter you re measuring to get the most accurate value.
If asphalt shingles are to be.
Locate the level s 12 inch mark.
Notes to the table above 1.
How do you calculate the slope of a roof.
The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run.
Some sources consider low slope to include 3 12 pitch roofs.
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.
Roof pitch is simply the slope created by the rafter.
The most precise way to find the roof s slope is by measuring it from the underside.
