Roof Pitch Ratio

It can be assessed in two ways either as the angle the rafter makes with the horizontal or the proportion between the rise and the run of the roof.

Roof pitch ratio.

They do not mean the same thing. Pitch is the incline of the roof represented as the ratio of rise to the span twice the run. Roof pitch is often expressed as a ratio between rise and run in the form of x 12. Pitch is thus the ratio of the rise in inches to a 12 inch run and is often expressed using a semicolon for example 6 12.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. The ridge height is 1 9 to 1 7th the span an angle of 12 5 to 16. A 12 to 24 pitch is expressed as 1 2. A ratio of 1 1 62 is known as the golden ratio and therefore the vast majority of roof pitch in degrees charts you see will be working to this ratio at the very least.

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. Roof pitch is simply the slope created by the rafter. So the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally. For example given a roof with a rise of 4 feet and a span of 24 feet the pitch is 1 to 6 pitch which can be expressed as the fraction of 1 6.

For example if the roof rises 4 feet and the span is 16 feet twice the run then the pitch is 4 16 or 1 4. Commonly used roof pitches were given names such as greek. A ratio of the ridge height to the width of the building span and as a ratio of the rafter length to the width of the building. 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.

Historically roof pitch was designated in two other ways. For example a pitch 1 12 means that per every twelve yards of building length the rise will be equal to one yard. Roof pitch is expressed as a ratio of the amount of the roof s vertical rise over a corresponding horizontal distance called the run pitch is written assuming a run of a foot or 12 inches so the ratio describes how much the roof rises for every foot of its run. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.

A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch. Often you express roof pitch as the ratio between the rise and the run in the form of x 12.