You can go by the measurements taken by walking the roof.
Roof slope 1 4 over 12 architectural note.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
Low slope roofs are from 0 to 3 12 in pitch.
A 4 in 12 slope can be expressed as the ratio of.
Note the roof material.
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.
See low slope roofing.
Some sources consider low slope to include 3 12 pitch roofs.
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.
Since this is a flat roof or nearly flat roof.
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.
This will give you the rise over run or pitch.
The table below shows common roof pitches and the equivalent grade degrees and radians for each.
However roof pitch is technically measured and defined differently and will not be discussed here.
A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope.
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.
Slopes greater than 18 12 are found on a frame roofs and some mansard style.
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.
I e 4 inches of rise per 12 inches one foot of run.
You can measure the roof slope on the bottom side.
If a roof rises 1 in a length of 12 this is 1 12 roof pitch.
For example if you measure 4 inches the pitch of your roof is 4 12.
4 12 is the incline of the roof expressed as.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
Roof slopes are most commonly defined by the rise over run ratio.
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.
Most roof s have a pitch in the 4 12 to 9 12 range.
The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run.
If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks.
Note that roof pitch is sometimes used in parallel with roof slope.