2 1 2 In 12 Roof Pitch

Roof pitch defined and explained.

2 1 2 in 12 roof pitch.

The table below shows common roof pitches and the equivalent grade degrees and radians for each. 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 designations are comprised of two numbers indicating a ratio. Or the colon can replace the slash as in 2 12 or 7 12.

For reference 2 12 equates to about 9 5º and 4 12 to about 18 5º. The maths behind this number is that it is the square root of rise run 2 1. The ratio can be indicated by a division slash separating the numbers such as 2 12 or 7 12. Some roof specifications may express slope in the typical geometric terms of degrees.

The combination of two numbers are used to display or show the roof pitch. A roof pitch multiplier also known as a roof pitch factor is a number that when multiplied by the area covered by a sloped roof gives the actual area of the roof. If a roof rises 1 in a length of 12 this is 1 12 roof pitch. If this isn t practical then perform the same measurement on the underside of the roof.

Most roof s have a pitch in the 4 12 to 9 12 range. Pitch is the term used to describe the angle slope or slant of your roof. 7 12 roof pitch 30 angle 30 26 degrees details. Image 1 12 to 12 12 roof pitch 7 12 pitch.

Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. 8 12 roof pitch 33 angle 33 69 degrees details 9 12 roof pitch 37 angle 36 37 degrees details. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof. Resilient asphalt shingles lie much flatter to the substrate than slate tile and concrete which keeps water from being easily blown under them.

At slopes below 2 12 a granule surfaced asphalt membrane can be installed and many are available in colors to complement the shingle colors. A pitch of 2 12 is the minimum pitch for shingles made of asphalt so your roof just barely makes the cut off for one of the most popular roofing material options.