When installing a P-trap, what is the maximum vertical distance from the fixture to the trap outlet?

The maximum vertical distance from the fixture to the trap outlet when installing a P-trap is 24 inches. This specification is crucial for ensuring that the trap functions correctly. A P-trap is designed to maintain a water seal that prevents sewer gases from entering the living space and to facilitate effective drainage of wastewater. If the vertical distance exceeds the allowable limit, it could lead to inadequate drainage, slow water emptying from the fixture, or even potential siphoning of the water seal, which may allow gases to escape into the building.

This 24-inch maximum distance is typically adhered to in plumbing codes to promote proper flow dynamics and minimize the risk of trap issues. It helps to ensure that the gravitational pull on the waste does not overpower the water seal, thus maintaining an effective barrier against odors. Understanding these guidelines is essential for proper plumbing design and installation, contributing to both functionality and safety within a plumbing system.