What is the maximum vertical distance from a fixture outlet to the trap weir?

The maximum vertical distance from a fixture outlet to the trap weir is 24 inches. This measurement is important for ensuring proper drainage and function of plumbing systems. If the distance exceeds this limit, it can lead to issues such as siphoning, where the water in the trap may be pulled out, allowing sewer gases to enter the living space and potentially leading to clogs. Maintaining a distance within the established guideline helps to promote efficient drainage by ensuring that the gravity flow of wastewater can occur properly. This standard is typically referenced in plumbing codes and practices, guiding inspectors in assessing the adequacy of plumbing installations.