8 27 2014 9 49 23 am.
1 4 per foot roof slope.
In commercial low slope roofing applications the roof has a slope of less than 3 inches per foot.
The most common slopes are.
Steep slope means that the roof has a slope of more than 3 inches per foot.
We can divide roofs into the following categories.
3 12 1 2 12 and 1 4 12.
The table below shows common roof pitches and the equivalent grade degrees and radians for each.
To put it in perspective the angle of this slope would be around 30 degrees.
If the slope is 4 12 the pitch for the 24 foot span is 1 6.
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.
The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.
18 4o inches per foot.
If the pitch is 1 3 the slope is 8 12.
Slope minimums for various roof coverings.
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.
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.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
Low slope or steep slope commercial application.
Roofs on most commercial buildings have at least a small slope of 1 4 inch.
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.
For example a pitch 1 12 means that per every twelve yards of building length the rise will be equal to one yard.
Flat roofs are not perfectly flat in reality they need a small slope for water runoff.
This means that for every horizontal foot the roof level goes up less than 3 inches vertically.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
4 3 1 slope.
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.
And pitch is a fraction derived by dividing the rise by the entire span.
Generally these roofs have a pitch from 1 2 12 to 2 12 from 4 2 to 16 7.
An example for a steep sloped roof is 8 12.
Most roof s have a pitch in the 4 12 to 9 12 range.
