This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
How to find the slope of a roof.
Rise run rise run slope.
Calculate the roof slope.
So in this case for every 12 inches the roof goes across horizontally b while rising 6 inches a there s actually 13 416 inches of roof c.
To do this simply convert the rise and run as a fraction to a decimal form eg.
The most precise way to find the roof s slope is by measuring it from the underside.
A 4 12 is a roof slope that rises by 4 inches for every 12 inches across.
If it doesn t have this mark use a tape measure to locate.
Once you know the roof slope multiplier for a particular slope you can use it to find the actual area of any size sloped roof with the same slope.
Locate the level s 12 inch mark.
First convert the pitch to a slope.
To find the angle of a roof in degrees convert the pitch to a slope then convert to degrees by finding the arc tangent of the slope.
There are a number of ways that you can calculate the roof slope of your home and you need to be aware of this.
If this isn t practical then perform the same measurement on the underside of.
How to convert roof pitch to degrees.
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.
Access one of the rafters then take the measurement this way.
Roof pitch calculator results explained.
This forms an angle of 18 5 between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low pitch and medium pitch roof.
Write the roof slope as the ratio of rise over run or vertical distance over horizontal distance.
When you want to replace or repair your roof you need to know about the slop of the roof the reason for this is the simple fact that roof slope can affect the overall cost of replacing or repairing the roof.
For example if your tape measure found a 6 inch vertical distance to the 12 inch mark on your level the slope is 6 12 or 6 in 12.