When calculating offsets in plumbing, what is NOT a standard measurement?

In plumbing measurements, "rise" and "run" are standard terms used to describe the vertical and horizontal distances that components must cover when calculating offsets. The "rise" refers to how high a pipe must elevate, while the "run" indicates the horizontal distance over which the pipe spans. These two measurements are critical for ensuring that the plumbing system maintains proper drainage and is installed at the correct angles.

On the other hand, the term "drop" can sometimes be relevant in specific contexts, such as when describing a downward slope from a higher to a lower point, particularly in drainage systems. However, it is not considered a standard measurement for calculating offsets in the same way that rise and run are.

The term "roll" does not align with the standard terminology employed in plumbing for offset calculations. While it might refer to other concepts in different fields (such as welding or framing), it does not apply here. Therefore, in the context of plumbing and the calculation of offsets, drop and roll are not recognized as standard measurements, making drop an appropriate choice for identifying what is not typically used in this calculation process.