Rise Over Run Roof Pitch

This is rarely is a whole number it is not a rare event and it is not a nightmare.

Rise over run roof pitch.

Other than the 45 roof slope which is 12 in 12 none of the standard roof pitches 5 in 12 6 in 12 etc are equal to a whole degree. If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12. I e 4 inches of rise per 12 inches one foot of run. The following table shows the roof pitch rise in run equivalents for all roof slopes in degrees from 1 to 72.

For example a roof that rises 4 inches for every 12 inches of run has a 4 12 pitch. 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. Drag sliders to animate the results and diagram. Visit this page using a phone or tablet to directly measure pitch and angles.

Enter run the flat level length then click pitch angle or rise to select then enter other known dimension angle or pitch. A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch. Roof pitch calculator the rise is the distance from the top of the roof to the bottom. Here is an online rise and run calculator which helps to calculate pitch slope and angle with the help of rise and run values.

Enter the rise and run for the pitch length and angle of the rafter. Roof slopes are most commonly defined by the rise over run ratio. The run is the distance from the outside of the wall to the inside of the ridge. 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.

It just means the top of the roof has to end out at a specific place. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot. Roof pitch is often expressed as a ratio between rise and run in the form of x 12. So a 3 inch rise roof also described as a 3 in 12 roof means that for every 12 or foot of horizontal distance the height of the roof increases by 3.

The same pitch is also sometimes written as 4 12 4 in 12 or 4 over 12. Roofers express roof slope as rise or pitch measured in inches of vertical rise per foot of horizontal distance or run. The triangle diagram will be re drawn to scale with all dimensions marked. A roof pitch that is based on a fixed rise and run and does not end up with a whole number is known as a bastard pitch.

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.