Roof Pitches in Degrees: What is the Common One Used by Builders?

We know that a lot of roofs are either pitched or flat. When it is a flat one, there are zero degrees of inclination involved here. When the roof is pitched, then there is a certain degree formed there. This is what they call roof pitches. Roof pitches are expressed in either degrees or a fraction.

If you wonder how high the roof pitches in degrees, keep reading and obtaining some information from this article.

Common Roof Pitches in Degrees

Standard roofs have a certain degree of inclination in it. The roof’s rise and span determine the inclination degree. But what are height and span?

roof rise and span
  • Rise is defined as the vertical height of a roof. In Cartesian coordinate system, you can say rise is analogous with the Y-axis.
  • Span is defined as the horizontal length of a roof. That said, the length should be measured perpendicularly. This is similar with the X-axis in Cartesian coordinate system. However, keep in mind that the span is only taking half of the horizontal measurement of the roof.

The inclination degree of a roof is also called roof pitches. Roof pitches in degrees are measured using a trigonometrical formula from the ratio between its rise and span. While for standard roof pitch charts, people typically use the fraction-type of the graph.

According to the chart, you can get various kinds of roof pitches. Starting from 0/12, 1/12, 2/12, and going all up to 12/12. Sometimes, people can even go with 15/12 or 18/12. Remember, the number shows the ratio of rising and span.

Read also: Joining two roofs with different pitches

For example, if the roof pitch is 8/12, then the roof height can be 400 cm while the span is 600 cm. That said, the span takes over only half of the horizontal length of the roof. If counted using the trigonometry formula, this 8/12 roof has a 33.69o roof pitch.

Roof Pitches in Degrees

What is the range of roof pitch degrees from 0/12 to 12/12? Counted using the formula, you can get that the inclination degree ranges from 0o-45o of roof inclination. For further explanation, each roof pitch has this standard roof pitch degree as follows:

  • 1/12 = 4.76o
  • 2/12 = 9.46 o
  • 3/12 = 14.04 o
  • 4/12 = 18.43o
  • 5/12 = 22.62 o
  • 6/12 = 26.57 o
  • 7/12 = 30.26 o
  • 8/12 = 33.69 o
  • 9/12 = 36.87 o
  • 10/12 = 39.81o
  • 11/12 = 42.51o
  • 12/12 = 45.00o

Common Roof Pitch Angles Used by Builders

According to sources, builders’ standard roof pitch is around 4/12 to 9/12, or when it is measured in degrees, it will be around 18.43o –36.87o.

Common Roof Pitch Angles Used by Builders

You may wonder why determining the roof pitches is essential in making the roof. Several reasons become necessary to detail it before making the rafters and other aspects related to roof-building.

First, it helps the builders to determine the type and size of materials that will be used. Given that it allows the builder to choose the materials used, it helps to estimate the durability. Talking about functionality, if there are appliances or any stuff required to be put in the roof, determining the roof pitches in degrees will help to ensure that the space is enough.

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RoofLast is an experienced author and roofing expert. With years of practical experience in the field authored several informative articles on various aspects of roofing, including installation, maintenance, and repair