What is the maximum allowed distance from the bottom of a fixture to the dip of the trap seal?

The maximum allowed distance from the bottom of a fixture to the dip of the trap seal is set at 10 inches. This measurement is critical for maintaining proper drainage and preventing sewer gases from entering the living space. The trap seal is an essential component of plumbing fixtures; it holds water that creates a barrier against sewer gases. If the distance exceeds 10 inches, there's a higher risk that the trap may not function properly. This could lead to a significant drop in the water level of the trap due to siphoning or evaporation, which compromises hygiene and safety.

Maintaining this distance is an important aspect of plumbing codes, ensuring that fixtures are installed in a way that protects occupants from the harmful effects of improper drainage and air quality issues. Having this knowledge is crucial for any plumbing professional, particularly in ensuring compliance with safety standards during installations and inspections.