Roof pitch is often expressed as a ratio between rise and run in the form of x 12.
Roof rise slope.
To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope.
Use a level against the underside of the rafter you re measuring to get the most accurate value.
Locate the level s 12 inch mark.
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.
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.
A 3 in 12 roof rises 3 for every 12 of run.
Low slope roofs are from 0 to 3 12 in pitch.
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.
A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch.
Roof pitch is simply the slope created by the rafter.
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.
A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope.
With regards to metal roofing the profile refers to the shape adopted by the metal sheets when they are bent to form the panels.
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.
Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.
3 of rise per 12 of run is the same as 1 of rise per 4 of run or 1 4 25.
Some sources consider low slope to include 3 12 pitch roofs.
Clearly once we get near 90.
How do you calculate the slope of a roof.
The minimum roof slope for metal roofs is dependent upon the roof profile.
Slopes greater than 18 12 are found on a frame roofs and some mansard style roofs.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
Access one of the rafters then take.
Notes to the table above 1.
The most precise way to find the roof s slope is by measuring it from the underside.
This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares.
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.
That s the same as a 14 degree slope or a 25 slope.
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.
Why is the roof slope 25.
For example a pitch 1 12 means that per every twelve yards of building length the rise will be equal to one yard.
