21 Degree Roof Pitch

Lower slopes don t handle wind driven rain as well.

21 degree roof pitch. The ratio can be indicated by a division slash separating the numbers such as 2 12 or 7 12. Divide the first part of the ratio by 12 to work out the pitch. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. 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.

This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. Or the colon can replace the slash as in 2 12 or 7 12. Find the inverse tangent of the pitch to find the angle in degrees. Roof pitch defined and explained.

Use the following formula which also describes a right triangle. The table below shows common roof pitches and the equivalent grade degrees and radians for each. Other than the 45 roof slope which is 12 in 12 none of the standard roof pitches 5 in 12 6 in 12 etc are equal to a whole degree. Steeper slopes increase the sail effect that makes them susceptible to wind.

Pitch is the term used to describe the angle slope or slant of your roof. The following table shows the roof pitch rise in run equivalents for all roof slopes in degrees from 1 to 72. A 30 degree roof slope 7 12 pitch is the right pitch to aerodynamically handle high wind. You can also calculate roof pitch even without using a roof slope calculator.

Here are the equations you may use to solve for the length of the slope and the rafter. What degree angle is a 12 12 pitch roof. With the use of this converter it will be easier for you to locate a 30 degree roof pitch 20 degree roof pitch 25 degree roof pitch or a 15 degree roof pitch. 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. The 30 degree 7 12 roof recommendation is backed up by testing according to the publication science daily. To convert between american roofing ratios and pitch degrees follow these steps. High pitched roofs often need extra fasteners and their pitch can be as high as 21 12.