What is the horizontal distance from the eaves to a point directly under the ridge referred to as?

The horizontal distance from the eaves to a point directly under the ridge is referred to as "run." This term is specifically used in roofing terminology to describe the horizontal measurement that extends from the edge of the roof (the eaves) up to the center point (beneath the ridge). Understanding this concept is crucial for accurately calculating various roof measurements, including pitch and slope, which are essential for determining proper drainage and structural integrity.

In contrast, "span" refers to the total width of the roof, which includes both sides from eave to eave. "Rise" is the vertical measurement from the top of the rafters to the height of the ridge, while "pitch" is the ratio of the rise to the run, indicating how steep the roof is. These terms are all related but have distinct meanings that are essential for roofing calculations.