How is roof pitch expressed?

Roof pitch is typically expressed by calculating the rise over the run, which is a ratio that compares the vertical height of the roof (the rise) to the horizontal distance from the peak to the edge (the run). This ratio is often represented in terms of inches, such as "4 in 12," which means that for every 12 inches run horizontally, the roof rises 4 inches vertically.

This method provides an easily understandable way to communicate roof angles, making it practical for builders and architects to design and construct roofs accurately. While other methods, like degrees or percentages, can also represent roof pitch, the rise over run measurement is deeply ingrained in construction practices, allowing for straightforward calculations of drainage, structural support, and material requirements.

Knowing how to use the rise over run method allows builders to accurately assess and install roofing, ensuring it meets design specifications and performs effectively in terms of water runoff and structural integrity.