What must be done to prove the plumbing fixtures are water tight after being set?

To determine whether plumbing fixtures are water-tight after being installed, conducting a visual inspection is beneficial but does not provide definitive proof of water tightness. Visual inspections primarily allow for the identification of obvious leaks or misalignments, but they might not reveal undetected issues.

The most effective method for ensuring that plumbing fixtures are completely water-tight is to perform a pressure test. This involves applying a specified amount of pressure to the plumbing system and observing if the pressure holds steady over a period. Any drop in pressure could indicate a leak, thereby proving that the fixtures are not entirely water-tight.

While other options, such as filling fixtures with dye or checking for noise during drainage, can suggest potential issues or assist in identifying leaks, they do not systematically confirm water tightness like a pressure test does. Pressure testing is a widely accepted practice specified in plumbing code to ensure that systems meet necessary standards for both safety and functionality. Thus, it is the most reliable method for proving that plumbing fixtures are entirely sealed against leaks.