Since this is a flat roof or nearly flat roof.
Roof slope 1 4 over 12 architectural note.
Note that roof pitch is sometimes used in parallel with roof slope.
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.
However roof pitch is technically measured and defined differently and will not be discussed here.
You can measure the roof slope on the bottom side.
This will give you the rise over run or pitch.
See low slope roofing.
If the rise is 4 feet over a 24 foot span then the roof pitch is 1 to 6 is expressed as a ratio and in inches per foot.
You can go by the measurements taken by walking the roof.
If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks.
4 12 is the incline of the roof expressed as.
I e 4 inches of rise per 12 inches one foot of run.
Low slope roofs are from 0 to 3 12 in pitch.
For example if you measure 4 inches the pitch of your roof is 4 12.
The table below shows common roof pitches and the equivalent grade degrees and radians for each.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
Most roof s have a pitch in the 4 12 to 9 12 range.
Simply locate a roof rafter board place the end of the level against the bottom edge and measure from the 12 inch mark vertically to the bottom edge of the rafter.
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.
If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12.
A 4 in 12 slope can be expressed as the ratio of.
1 12 roof pitch angle 4 76 degrees.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 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.
Some sources consider low slope to include 3 12 pitch roofs.
Note the roof material.
Roof slopes are most commonly defined by the rise over run ratio.
If a roof rises 1 in a length of 12 this is 1 12 roof pitch.
0 pitch 1 00x the roof area.
The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run.