What is the maximum number of side by side clothes washers allowed on a 4 inch horizontal waste?

The maximum number of side-by-side clothes washers allowed on a 4-inch horizontal waste is defined by plumbing codes to ensure proper drainage and to prevent clogs due to excess flow. In this case, the figure of 22 is established based on the capacity that a 4-inch waste line can effectively handle.

When multiple fixtures are connected to a single drain line, it’s crucial to consider the waste flow rate and potential for backflow. A limit of 22 side-by-side clothes washers ensures that the waste line operates efficiently without overloading it, allowing for proper venting and drainage. This figure is derived based on hydraulic calculations and accepted plumbing practices that promote effective drainage and minimize the risk of plumbing issues.

Other numbers, such as 30, 41, or 50, exceed the recommended capacity for a 4-inch horizontal waste, which could lead to complications in flow and increase the likelihood of drain blockage, causing inefficiencies in the plumbing system.