27 Degree Roof Pitch
Find the inverse tangent of the pitch to find the angle in degrees.
27 degree roof pitch. To convert between american roofing ratios and pitch degrees follow these steps. Lower slopes don t handle wind driven rain as well. 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. To see roof pitch visual examples how to determine pitch.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. The following table shows how the same common roof slopes can be expressed using rise in run ratios degrees and percentages. 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. You have to pay higher cost for steeper pitch.
A 30 degree roof slope 7 12 pitch is the right pitch to aerodynamically handle high wind. The table below shows common roof pitches and the equivalent grade degrees and radians for each. Look at the column labeled pitch then look under degrees to get the corresponding amount of degrees. Steeper slopes increase the sail effect that makes them susceptible to wind.
Divide the first part of the ratio by 12 to work out the pitch. A 12 12 pitch roof has a pitch angle of 45. 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. This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees.
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. It s just a little math. Using pitch its footprint and basic geometry you can quickly and with a high degree of accuracy calculate the length of the gable sides. See below after the table for directions on how to convert any roof slope from one form to another even roof slopes not shown in the table.
The 30 degree 7 12 roof recommendation is backed up by testing according to the publication science daily. Measurement of your house roof pitch is one of the most important things while constructing pitched roof. For example a 3 pitch or 3 in 12 pitch or 3 12 pitch all mean that the roof rises 3 inches for every 12 inches of it s horizontal run. However if you to do the process using your own knowledge you can still convert pitch to degrees by dividing the rise and run and get its corresponding measurement.
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. 8 12 pitch 33 75 degrees. Also see our page quick reference.