How is the slope of a roof typically expressed?

The slope of a roof is typically expressed as a ratio of rise to run because this method provides a clear understanding of the angle of the roof in relation to its horizontal distance. The "rise" refers to how much the roof elevates vertically, while the "run" refers to the horizontal distance over which that elevation occurs. This ratio effectively communicates the steepness or pitch of the roof, which is essential for various roofing applications, including drainage and aesthetics.

Using a rise-to-run ratio is advantageous because it allows for standardized comparisons, making it easier for roofers to communicate designs and for builders to ensure that roofing materials are suitable for the chosen slope. While other methods such as percentages or degrees can also describe slope, the rise-to-run ratio is the most commonly utilized format in the roofing industry due to its clarity and utility.