Journeyman Plumber ExamFixtures, Faucets, and Other AppliancesMedium
A plumber is installing a washing machine. The washing machine standpipe for the drain must extend a certain distance above the trap weir to prevent suds or wastewater from overflowing the standpipe during discharge. What is the minimum height required for the standpipe above the trap weir, according to UPC standards?
- A36 inches (914 mm)
- B18 inches (457 mm)
- C24 inches (610 mm)
- D30 inches (762 mm)
Show answer & explanationAnswer & explanation
Correct answer: B. 18 inches (457 mm)
According to UPC 2021, Section 804.1, the standpipe for a clothes washer shall extend not less than 18 inches (457 mm) and not more than 30 inches (762 mm) above the trap weir.
Why the other options are wrong
- A. 36 inches exceeds the maximum height permitted by UPC and could lead to drainage issues.
- C. 24 inches is within the acceptable range but not the minimum.
- D. 30 inches is the maximum height allowed for a standpipe above the trap weir, not the minimum.
Washing Machine Standpipe Height
The required vertical distance of a washing machine drain standpipe above its trap weir, as stipulated by plumbing codes.
- UPC minimum: 18 inches (457 mm).
- UPC maximum: 30 inches (762 mm).
- Prevents suds overflow and machine discharge issues.
Memory trick: Standpipe's height for the wash, 18 is the low, 30 is the high, no gush!