How To Find The Slope Of A Roof

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.

How to find the slope of a roof.

Slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run this is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. Calculate the roof slope. Write the roof slope as the ratio of rise over run or vertical distance over horizontal distance. There are a number of ways that you can calculate the roof slope of your home and you need to be aware of this.

A 4 12 is a roof slope that rises by 4 inches for every 12 inches across. Use a level against the underside of the rafter you re measuring to get the most accurate value. If it doesn t have this mark use a tape measure to locate. 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.

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. 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. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. How to convert roof pitch to degrees.

The most precise way to find the roof s slope is by measuring it from the underside. To do this simply convert the rise and run as a fraction to a decimal form eg. Access one of the rafters then take the measurement this way. First convert the pitch to a slope.

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. Locate the level s 12 inch mark. If this isn t practical then perform the same measurement on the underside of. Rise run rise run slope.

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.