What is the minimum length required for a clothes washer standpipe?

The minimum length required for a clothes washer standpipe is 18 inches. This specification is important because it ensures that the standpipe can effectively handle the discharge from the washer without causing issues such as siphoning or backflow. An 18-inch height allows for adequate water flow and drainage, helping to prevent blockages and ensuring efficient operation of the washing machine. Additionally, having a properly sized standpipe contributes to the overall plumbing system's functionality and health by preventing potential flooding or cross-contamination with wastewater. This height standard has been established in plumbing codes to ensure safety and efficiency in residential plumbing systems.