Standard Roof Pitch Angles

They have a pitch ranging from 4 12 to 9 12.

Standard roof pitch angles.

Roof pitch varies depending on culture climate style and available materials. If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks. Commonly it is 3 4 th of span as per gothic rafter must be equal to span. The 12 inch run is considered standard in roof pitch or angle terminologies.

Use the following formula which also describes a right triangle. The most commonly used roof pitches fall in a range between 4 12 and 9 12. So use the 12 inch level as a constant run and 18 inch ruler as a variable rise. 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.

You can also calculate roof pitch even without using a roof slope calculator. Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled. Greek says one must keep rafter length in range of 1 9 to 1 7 th of span but as per roman style the standard dimensions are kept about 1 3 to 2 9 th of span with an angle of 23 to 24 degree. Some sources consider low slope to include 3 12 pitch roofs.

High pitched roofs often need extra fasteners and their pitch can be as high as 21 12. 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. In the usa the range of standard pitches is anywhere between 4 12 and 9 12. Find all the needed factors in order to determine the pitch angle s degree.

Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs. Pitches above 9 12 are very highly angled and are designated steep slope roofs. With insufficient pitch a roof can leak rain and with a pitch too great its stones will fall loose. Usually average roof pitch is determined using the same roof length method.

Locate its tangent or tan and follow the left row for you to read its corresponding degree. Low slope roofs are from 0 to 3 12 in pitch. Display of roof pitches 1 12 through 18 12. 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.

Roof pitch and corresponding angles. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. In the uk the typical house has a pitch between 40 50 although 45 should be avoided. So the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally.