1 8 Roof Slope

Coal tar built up roofs however can have a design roof slope of 1 8 12 1 percent but no less.

1 8 roof slope.

The most precise way to find the roof s slope is by measuring it from the underside. 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. Roof pitch calculator results explained.

The calculator above can handle much of this math. 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. 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.

Measure with a speed square. For instance if you travel 3 inches vertically and 3 feet 36 inches horizontally the slope would be 3 36 or 1 12. This means that the rise of the slope goes up or down 8 inches for every 12 inches. A roof that rises 8 feet over a 24 foot span was said to have a 1 to 3 pitch.

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. An example for a steep sloped roof is 8 12. The pitch of this roof is 4 8 12. The maths behind this number is that it is the square root of rise run 2 1.

Slope gradients are written as y x where y is a single unit in rise and x is the run. 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. You can go by the measurements taken by walking the roof. Built up roofs must have a design roof slope of 1 4 12 or greater 2 slope.

Either way let s see how you can calculate the slope of a roof without using a roof slope calculator. 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. Minimum roof slope roof pitch r905 9 1. Calculating a slope gradient.

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. If the rise is 4 feet over a 24 foot span then the roof pitch was said to be 1 to 6 the pitch can be expressed numerically as a fraction. Access one of the rafters then take the measurement this way.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Measuring the slope from the rafters. A speed square and level can be used to easily find the pitch of a roof.