Roof Slope Pitch Angle

Often you express roof pitch as the ratio between the rise and the run in the form of x 12.

Roof slope pitch angle.

Angle the angle of a roof is the same as the roof s slope except instead of being represented as x 12 it is represented in degrees. The combination of two numbers are used to display or show the roof pitch. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across. 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.

Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. Rise run rise run slope. First convert the pitch to a slope. Roof pitch angle and slope factor charts.

You can assess this in two ways either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof. Squaring building lines example 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 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. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length. To do this simply convert the rise and run as a fraction to a decimal form eg.