Pitch Roof Slope Angle

Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof.

Pitch roof slope angle.

Thus a 4 12 pitch would be a 33 slope. Roof pitch refers to the slope which the rafter creates. The minimum roof pitch for shedding snow is around 30 or a 6 12 or 7 12 slope although this is not a definite as the material of your roof the direction of the snow and wind are some factors that can affect whether or not snow will slide as roofs of as little as 10 have been reported to shed snow. Rise run rise run slope.

A 4 12 pitch is around 18 5 degrees but not exactly. 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. 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 divide the rise over run multiply by 100 and get a percentage.

First convert the pitch to a slope. 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. 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. A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible.

Roof pitch angle and slope factor charts. The combination of two numbers are used to display or show the roof pitch. Often you express roof pitch as the ratio between the rise and the run in the form of x 12.