Roof Pitch Conversion Factor

Then you ll be able to measure slope from an unfinished attic space under the roof.

Roof pitch conversion factor.

Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot. A roof pitch multiplier also called a roof pitch factor is a number that is multiplied by the area covered by a sloped roof to produce the area of the actual surface of the roof. The roof pitch is important in determining the appropriate installation method and how much roofing material will be needed. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof.

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. Roof pitch is used to describe the slope or angle of the roof. 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.

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. The headache of using pythagoras and trigonometry can be spared by making use of these charts. 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. 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.