Roof Slope Pitch Angle

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

Roof slope pitch angle.

Roof pitch refers to the slope which the rafter creates. First convert the pitch to a slope. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. Roof pitch angle and slope factor charts.

Roof pitch is a term describing how steep or flat your roof slope is. 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. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across.

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

To do this simply convert the rise and run as a fraction to a decimal form eg. 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.