Which dimension is NOT typically measured when sizing a cleanout?

When sizing a cleanout, the dimensions that are typically measured are diameter and height. The diameter is crucial because it determines the opening size of the cleanout, which should be sufficient to allow for proper access for cleaning and maintenance. Height is also measured to ensure that the cleanout is appropriately positioned for accessibility within the plumbing system.

Length and width, while they may be relevant in some contexts, are not standard measurements taken into account when sizing a cleanout specifically. Therefore, length is not a typical dimension measured for cleanouts, as the focus is primarily on the overall diameter and height to ensure functionality and access for cleaning purposes.