Roof Pitch Numbers

Roof pitch and corresponding angles.

Roof pitch numbers.

Pitch rise run 1 5 6 25. The ridge height is 1 9 to 1 7th the span an angle of 12 5 to 16. The rafters equal the span. How to measure roof pitch.

Commonly used roof pitches were given names such as greek. Often you express roof pitch as the ratio between the rise and the run in the form of x 12. For example a roof that rises 6 inches for every 12 inches of horizontal run has a 6 in 12 pitch. The 7 means that the roof rises 7 for every 12 it runs.

Pitches above 9 12 are very highly angled and are designated steep slope roofs. Roof pitch calculator is determined by the number of inches it rises vertically for every 12 inches it extends horizontally. Also referred to as roof slope or roof slant so what does the 7 12 in the example to the right mean. The ridge height is 2 9ths to 1 3 the span an angle of 24 to 34.

This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch. If a roof increases in height by four inches for every foot of horizontal run it is considered to have a 4 in 12 pitch or just a 4 pitch talk in terms of pitches and you will always be understood in the roofing universe. The most commonly used roof pitches fall in a range between 4 12 and 9 12.

So the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally. Recalculate this value into an angle. Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m. 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.

Angle arctan pitch arctan 0 25 14. Finally you can find the roof pitch in the form of x 12. The angle or pitch of a roof is calculated by the number of inches it rises vertically for every 12 inches it extends horizontally. 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.

The rafter length is 3 4 the span about 48. Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs. Roof pitch refers to the slope which the rafter creates. Calculate the roof pitch as the proportion of rise and run.

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. Pitch is thus the ratio of the rise in inches to a 12 inch run and is often expressed using a semicolon for example 6 12.