How deep can fixtures be placed when they are combined?

When fixtures are combined, they should be installed at a uniform depth to maintain proper drainage and prevent issues related to water flow and pressure. Placing fixtures at different depths can complicate the plumbing system, leading to potential blockages or uneven water distribution.

The correct specified depth difference when fixtures are combined is 6 inches. This limit of 6 inches allows for a level of flexibility in installation while still adhering to plumbing codes and standards that aim to ensure effectiveness in drainage and prevent any possible backflow issues between fixtures. It ensures that pipes align appropriately and minimizes the risk of creating additional stresses or blockages in the plumbing system.

In this context, choosing 6 inches as the maximum depth difference ensures that the plumbing design remains functional and reliable, which is crucial for compliance with Massachusetts plumbing regulations.