Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.
Pitch factor for roof.
There are many websites which are offering this facility.
The whole table of roof pitch and slope gives a conversion factor so as to obtain a numerical figure of the slope.
On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
High pitched roofs often need extra fasteners and their pitch can be as high as 21 12.
Conventional roofs are the easiest to construct and you can walk on them safely.
They have a pitch ranging from 4 12 to 9 12.
This numerical figure is significant as not everybody can understand the technical measurements.
You can use this roof slope calculator.
You can also calculate roof pitch even without using a roof slope calculator.
For this example suppose the roof is 20 ft wide measured from the roof.
Here let s assume the pitch is 6 12.
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.
This will give you the rise over run or pitch.
The roof pitch is described as rise in run which is 12 units.
A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch.
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.
Pitch is thus the ratio of the rise in inches to a 12 inch run and is often expressed using a semicolon for example 6 12.
For example if you measure 4 inches the pitch of your roof is 4 12.
You just need to go to any of those websites and there insert the required information and they will tell you your roof pitch factor.
A roof pitch multiplier also called a roof pitch factor is a number that is multiplied by the area covered by a sloped roof to produce the area of the actual surface of the roof.
The maths behind this number is that it is the square root of rise run 2 1.
Another option that is available for you in finding the pitch factor for your roof is to find roof pitch factor calculator online.
Step by step example using the roof pitch factor table measure the dimensions covered by the roof.
For roof slopes expressed as x in 12 rise in run the roof pitch multiplier is determined by finding the square root of rise run 1.
Roof pitch and corresponding angles.
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.
