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.
Roof pitch conversion factor.
In essence a roof pitch chart is provided as a rough guide usually by a roofing company.
Often you express roof pitch as the ratio between the rise and the run in the form of x 12.
Roof pitch and corresponding angles.
Roof pitch refers to the slope which the rafter creates.
It is sometimes called the roof pitch multiplier.
A roof pitch multiplier also called a roof pitch factor is a number that is multiplied by the area covered by a sloped roof to produce the area of the actual surface of the roof.
The roof pitch conversion factor is a number that when multiplied by the area covered by the roof gives an estimate the total surface area of the sloped roof itself.
The roof slope factor chart also consists of conversion factors to determine the slope.