Run Of Roof Definition

The pitch of a roof is its vertical rise over its horizontal span.

Run of roof definition.

A roof is the top covering of a building including all materials and constructions necessary to support it on the walls of the building or on uprights providing protection against rain snow sunlight extremes of temperature and wind. 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. A 3 in 12 roof rises 3 for every 12 of run. This is the slope of geometry stairways and other construction disciplines or the trigonometric arctangent function of its decimal.

This article series gives clear examples just about every possible way to figure out any or all roof dimensions and measurements expressing the roof area width length slope rise run and unit rise in inches per foot. 3 of rise per 12 of run is the same as 1 of rise per 4 of run or 1 4 25. That s the same as a 14 degree slope or a 25 slope. A roof is part of the building envelope.

Roof pitch is often expressed as a ratio between rise and run in the form of x 12. The horizontal change in distance or the horizontal distance covered by an un supported rafter or truss. Roof pitch is simply the slope created by the rafter. 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.

This table lists all of the common roof slopes expressed as rise run roof angle roof slope slope grade and walk ability.