Standard Roof Pitch Angles

Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs.

Standard roof pitch angles.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Commonly it is 3 4 th of span as per gothic rafter must be equal to span. You can also calculate roof pitch even without using a roof slope calculator. In the usa the range of standard pitches is anywhere between 4 12 and 9 12.

So use the 12 inch level as a constant run and 18 inch ruler as a variable rise. Usually average roof pitch is determined using the same roof length method. 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. 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.

The most commonly used roof pitches fall in a range between 4 12 and 9 12. Some sources consider low slope to include 3 12 pitch roofs. Locate its tangent or tan and follow the left row for you to read its corresponding degree. The 12 inch run is considered standard in roof pitch or angle terminologies.

Low slope roofs are from 0 to 3 12 in pitch. Use the following formula which also describes a right triangle. This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. 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. 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. Pitches above 9 12 are very highly angled and are designated steep slope roofs. They have a pitch ranging from 4 12 to 9 12.

High pitched roofs often need extra fasteners and their pitch can be as high as 21 12. So the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally. Thatch is one of the oldest roofing materials and needs a steep pitch to drain properly some types of stone roofs have a very restrictive roof pitch. Find all the needed factors in order to determine the pitch angle s degree.

With insufficient pitch a roof can leak rain and with a pitch too great its stones will fall loose. Display of roof pitches 1 12 through 18 12. In the uk the typical house has a pitch between 40 50 although 45 should be avoided. There is no standard universal roof pitch.