Either way let s see how you can calculate the slope of a roof without using a roof slope calculator.
1 8 roof slope.
This means that the rise of the slope goes up or down 8 inches for every 12 inches.
Minimum roof slope roof pitch r905 9 1.
The pitch of this roof is 4 8 12.
Roof pitch calculator results explained.
Slope gradients are written as y x where y is a single unit in rise and x is the run.
This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit.
A speed square and level can be used to easily find the pitch of a roof.
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.
To put it in perspective the angle of this slope would be around 30 degrees.
The maths behind this number is that it is the square root of rise run 2 1.
Angle the angle of a roof is the same as the roof s slope except instead of being.
0 pitch 1 00x the roof area.
This is read as a one in twelve slope.
Access one of the rafters then take the measurement this way.
Since this is a flat roof or nearly flat roof.
Measure with a speed square.
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.
Measuring the slope from the rafters.
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.
For instance if you travel 3 inches vertically and 3 feet 36 inches horizontally the slope would be 3 36 or 1 12.
Calculating a slope gradient.
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.
Coal tar built up roofs however can have a design roof slope of 1 8 12 1 percent but no less.
An example for a steep sloped roof is 8 12.
The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.
Both numbers must use the same units.
You can go by the measurements taken by walking the roof.
A roof that rises 8 feet over a 24 foot span was said to have a 1 to 3 pitch.
Set the level on the edge of the speed square as shown below then place the heel of the speed square on a rafter or gable edge of the roof.
The most precise way to find the roof s slope is by measuring it from the underside.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
