You can go by the measurements taken by walking the roof.
1 to 2 roof slope.
A 1 2 percent slope is used for applications that involve drainage of land and concrete such as patios and sidewalks.
A 2 12 roof slope means your roof has 2 inches of vertical drop for every 12 inches of horizontal distance.
A roof pitch multiplier also known as a roof pitch factor is a number that when multiplied by the area covered by a sloped roof gives the actual area of the roof.
0 pitch 1 00x the roof area.
Roof pitch designations are comprised of two numbers indicating a ratio.
That means the roof doesn t shed water as easily as steeper roofs which is why choosing the right type of roofing material is so important.
The ratio can be indicated by a division slash separating the numbers such as 2 12 or 7 12.
These roofs have a pitch less than 4 12.
1 pitch 1 01 2 pitch 1 02 3 pitch 1 03 4 pitch 1 05 5 pitch 1 085 6 pitch 1 12 7 pitch 1 16 8 pitch 1 21 9 pitch 1 25 10 pitch 1 31 11 pitch 1 36 12 pitch 1 42.
Standing seam roof systems must have a minimum roof slope of 1 4 12 2 slope.
For example given a roof with a rise of 4 feet and a span of 24 feet the pitch is 1 to 6 pitch which can be expressed as the fraction of 1 6.
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.
Or the colon can replace the slash as in 2 12 or 7 12.
A 12 to 24 pitch is expressed as 1 2.
Simply put it s a shallow roof.
Roof pitch defined and explained.
Since this is a flat roof or nearly flat roof.
This means for every 12 horizontal units the roof must rise a minimum of one half vertical unit.
The maths behind this number is that it is the square root of rise run 2 1.
Most roof s have a pitch in the 4 12 to 9 12 range.
It also figures significantly in conservation farming irrigation where the land most vulnerable to rain erosion gets a 1 2 percent slope.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
The term pitch and slope are often used interchangeably which is incorrect.
The table below shows common roof pitches and the equivalent grade degrees and radians for each.
Pitch is the term used to describe the angle slope or slant of your roof.
Generally such roofs have a pitch ranging from 1 2 12 to 2 12.
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.