1 8 Roof Slope

To put it in perspective the angle of this slope would be around 30 degrees.

1 8 roof slope.

This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit. The pitch of this roof is 4 8 12. Since this is a flat roof or nearly flat roof. This means that the rise of the slope goes up or down 8 inches for every 12 inches.

Both numbers must use the same units. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. The maths behind this number is that it is the square root of rise run 2 1. Measure with a speed square.

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. Access one of the rafters then take the measurement this way. Measuring the slope from the rafters. A roof that rises 8 feet over a 24 foot span was said to have a 1 to 3 pitch.

Either way let s see how you can calculate the slope of a roof without using a roof slope calculator. A speed square and level can be used to easily find the pitch of a roof. 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. 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.

This is read as a one in twelve slope. An example for a steep sloped roof is 8 12. Calculating a slope gradient. Minimum roof slope roof pitch r905 9 1.

Slope gradients are written as y x where y is a single unit in rise and x is the run. 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. The calculator above can handle much of this math. For instance if you travel 3 inches vertically and 3 feet 36 inches horizontally the slope would be 3 36 or 1 12.

The most precise way to find the roof s slope is by measuring it from the underside. 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. Angle the angle of a roof is the same as the roof s slope except instead of being. The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.

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. 0 pitch 1 00x the roof area.