What do you call the distance the rafters rise per foot of run?

The term that describes the distance the rafters rise per foot of run is known as the "Unit of Rise." This term is crucial in roofing and framing as it allows builders to calculate the slope of the rafters accurately. The unit of rise is typically expressed as a ratio, indicating how many units it rises for each horizontal unit of run. Understanding this concept helps in determining the angle of the rafters, which is vital for ensuring adequate water drainage and structural integrity of the roof.

In contrast, total rise refers to the overall vertical distance from the highest point of the roof to the lowest point or the ground level, which does not provide the ratio necessary for calculating slope. Line length pertains to the actual length of the rafter from the ridge to the wall, which is useful for determining material lengths but does not relate to the rise per foot of run. Cut or slope, while related to the pitch of the roof, does not specifically define the rise per run in a ratio format, which is key for calculating angles and ensuring correct framing.