What is the standard maximum distance a trap can be from the fixture it serves?

The standard maximum distance a trap can be from the fixture it serves is generally accepted to be 24 inches. This distance is crucial for ensuring that the trap can effectively retain water, which acts as a barrier to prevent sewer gases from escaping into the living space. It also helps in maintaining proper drainage by allowing the wastewater to flow smoothly into the drainage system without creating air pockets or vacuum conditions that could lead to malfunction.

When the trap is positioned beyond this maximum distance, there can be increased risks of siphoning or evaporation of the trap seal, which could compromise its effectiveness. The 24-inch limit provides a balance between accessibility for installation or maintenance and the functional reliability of the plumbing system. Adhering to this guideline is essential for meeting plumbing codes and ensuring a safe, effective plumbing system.