Standard Roof Slope Angle

So if your roof rises 4 inches for every 12 inches of horizontal length then the pitch of your roof is expressed as 4 12.

Standard roof slope angle.

Low slope roofs are from 0 to 3 12 in pitch. Rise run rise run slope. 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.

See low slope roofing. Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled. Pitch angle incline slope they all can be used to refer to the steepness of a roof. 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.

To find the angle of a roof in degrees convert the pitch to a slope then convert to degrees by finding the arc tangent of the slope. First convert the pitch to a slope. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs.

Find all the needed factors in order to determine the pitch angle s degree. This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. Pitches above 9 12 are very highly angled and are designated steep slope roofs. A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible.

Often you express roof pitch as the ratio between the rise and the run in the form of x 12. The 12 inch run is considered standard in roof pitch or angle terminologies. If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

To do this simply convert the rise and run as a fraction to a decimal form eg. The way pitch also known as roof slope is measured is rise over run. Some sources consider low slope to include 3 12 pitch roofs. Roof pitch refers to the slope which the rafter creates.

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. Roof pitches exceeding the level of 9 12 or approximately 37 degrees are termed steep slope roofs. The most commonly used roof pitches fall in a range between 4 12 and 9 12. If we consider the commercial applications then low sloop type roofs are preferred with pitch ranging from 2 12 to 4 12.