Journeyman Plumber ExamDrainage, Waste, and Venting (DWV) SystemsMedium
A plumber is installing a main building drain. What is the maximum distance a cleanout can be located from the upstream end of a horizontal drainage pipe?
- A100 feet (30.5 meters)
- B50 feet (15.2 meters)
- C25 feet (7.6 meters)
- D75 feet (22.9 meters)
Show answer & explanationAnswer & explanation
Correct answer: A. 100 feet (30.5 meters)
Most plumbing codes require cleanouts to be installed no more than 100 feet (30.5 meters) apart in horizontal drainage lines, and also at the upstream end of any such line, changes in direction, or where pipes connect to others.
Why the other options are wrong
- B. 50 feet is a common spacing for certain situations but not the maximum for general horizontal runs.
- C. 25 feet is too frequent for general cleanout spacing, though required at specific points like changes in direction.
- D. 75 feet is not a standard maximum spacing for cleanouts in most codes.
Cleanout Spacing
The maximum allowable distance between access points (cleanouts) in a drainage system to facilitate pipe cleaning.
- Ensures accessibility for snaking/clearing blockages.
- Required at specific intervals and locations.
- Prevents extensive pipe removal for maintenance.
Memory trick: Access for all, every 100 feet, or a clog's defeat!