Roof Pitch Conversion Factor

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.

Roof pitch conversion factor.

Roof pitch is used to describe the slope or angle of the roof. In essence a roof pitch chart is provided as a rough guide usually by a roofing company to help you see what the average roof pitches tend to be. To obtain an accurate roof pitch measurement properly measure the rise and run. Then you ll be able to measure slope from an unfinished attic space under the roof.

Usually they come in the form of a roof pitch diagram chart but other times it will be presented to you in a conversion format. For roof slopes expressed as x in 12 rise in run the roof pitch multiplier is determined by finding the square root of rise run 1. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot. A 10 slope roof should not be confused with a 10 pitch roof as a 10 slope roof means that the roof rises by ten inches for every foot of run.

The combination of two numbers are used to display or show the roof pitch. Using a tape measure make a pencil mark 12 inches from the end of a carpenter s level. The roof slope factor chart also consists of conversion factors to determine the slope of the roof. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof.