18 Degree Roof Pitch

The following table shows the roof pitch rise in run equivalents for all roof slopes in degrees from 1 to 72.

18 degree roof pitch.

A 4 12 slope is enough to accommodate water runoff but is not suitable for regions that are affected by heavy snowfall. 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 refers to the slope which the rafter creates. Common roof pitches and equivalent grade degree and radian angles most roof s have a pitch in the 4 12 to 9 12 range.

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. This forms an angle of 18 5 between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low pitch and medium pitch roof. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope flat. 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.

In most cases the angle of inclination is chosen in the range from 11 to 45 but other values are encountered. Roof pitch and corresponding angles. If you are looking at a roof plan for your home or business very rarely will it list the roof pitch in degrees instead it lists the rise and the run of the roof. It is uncommon to find a roof below 15 but for those very low pitch applications there are interlocking clay pantiles available suitable for use down to 12 5.

Find all the needed factors in order to determine the pitch angle s degree. Locate its tangent or tan and follow the left row for you to read its corresponding degree. Traditionally a minimum roof pitch of 20 was recommended in bs 5534 but modern tiles and slates have now been designed for applications as low as 15. Main methods of calculating roof pitch calculation of the slope of the roof is an important part of the design process of its construction.

This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. So use the 12 inch level as a constant run and 18 inch ruler as a variable rise.