This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
1 4 per foot roof slope.
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.
An example for a steep sloped roof is 8 12.
The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.
This means that the rise of the slope goes up or down 8 inches for every 12 inches.
The most common slopes are.
Remember slope is expressed as a ratio and in inches per foot.
A 12 12 roof pitch would be selected as 12 inches of rise per foot with no fraction and the value generated by the calculator would be 45º.
Strangely enough if a pitch of 6 inches rise per foot is entered then the degrees generated is not 22 5º it is 26 6º.
Generally these roofs have a pitch from 1 2 12 to 2 12 from 4 2 to 16 7.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
If the slope is 4 12 the pitch for the 24 foot span is 1 6.
Most roof s have a pitch in the 4 12 to 9 12 range.
This means that for every horizontal foot the roof level goes up less than 3 inches vertically.
Roofs on most commercial buildings have at least a small slope of 1 4 inch.
The table below shows common roof pitches and the equivalent grade degrees and radians for each.
We can divide roofs into the following categories.
Slope minimums for various roof coverings.
3 12 1 2 12 and 1 4 12.
Steep slope means that the roof has a slope of more than 3 inches per foot.
A low slope roof is one whose slope is less than 3 12.
Flat roofs are not perfectly flat in reality they need a small slope for water runoff.
4 3 1 slope.
Low slope or steep slope commercial application.
In commercial low slope roofing applications the roof has a slope of less than 3 inches per foot.
For example a pitch 1 12 means that per every twelve yards of building length the rise will be equal to one yard.
A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof.
18 4o inches per foot.
If the pitch is 1 3 the slope is 8 12.
And pitch is a fraction derived by dividing the rise by the entire span.
When looking at metal roofing panel you will need to consult with the manufacturer to ensure that the metal panel you selected will work for your application.
