Carpenters do not refer to the angle of roof as 30 but prefer to use the pitch of the roof.
Unit for pitch of a roof.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch.
Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio.
However most often a ratio of pitch also fraction is slang used for the more useful slope of rise over run of just one side half the span of a dual pitched roof.
Pitch tan angle use this when you express the angle of the roof pitch in degrees what is the standard pitch of a roof.
The pitch fraction represents a certain amount of vertical rise over the entire span.
Roof pitch varies depending on culture climate style and available materials.
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.
A 12 to 24 pitch is expressed as 1 2.
The pitch of a roof is its vertical rise over its horizontal span.
There is no standard universal roof pitch.
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.
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.
The roof s pitch is its vertical rise divided by its horizontal span or run called slope in geometry or the tangent function in trigonometry.
Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.