1 To 4 Ratio Roof Slope

Most roof s have a pitch in the 4 12 to 9 12 range.

1 to 4 ratio roof slope.

The pitch of a roof is its vertical rise over its horizontal span. Roof pitch is often expressed as a ratio between rise and run in the form of x 12. Horizontal to vertical slope ratio to 1 percent slope degrees slope slope ratio. Flat roofs which aren t perfectly flat require a small slope to allow for water runoff.

Generally such roofs have a pitch ranging from 1 2 12 to 2 12. For instance if you travel 3 inches vertically and 3 feet 36 inches horizontally the slope would be 3 36 or 1 12. 4 3 1 slope. We can divide roofs into the following categories.

A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope. 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. You can go by the measurements taken by walking the roof. Calculating a slope gradient.

The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run. Often you express roof pitch as the ratio between the rise and the run in the form of x 12. The table below shows common roof pitches and the equivalent grade degrees and radians for each. 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.

This is read as a one in twelve slope. 18 4o inches per foot. Slope gradients are written as y x where y is a single unit in rise and x is the run. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof.

3 1 or 3 to 1 percent slope. Flat roofs are not perfectly flat in reality they need a small slope for water runoff. You can divide roofs into these categories. Both numbers must use the same units.

This is the slope of geometry stairways and other construction disciplines or the trigonometric arctangent function of its decimal. Since this is a flat roof or nearly flat roof. For example a pitch 1 12 means that per every twelve yards of building length the rise will be equal to one yard. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

If the rise is 6 inches for every 12 inches of run then the roof slope is 6 in 12 the slope can be expressed numerically as a ratio.