What is the maximum allowable distance for a trap arm from the trap to the vent?

The maximum allowable distance for a trap arm from the trap to the vent is correctly identified as 5 feet. This distance is established to ensure proper drainage and venting. If the trap arm exceeds this length, it can lead to various plumbing issues, such as siphoning of the trap, which would allow sewer gases to enter the building and can also lead to clogs due to inadequate ventilation.

Maintaining the trap arm within this limit helps ensure that the system can effectively eliminate waste and maintain negative pressure necessary for drainage without allowing wastewater to backflow. This distance is a critical aspect of plumbing codes designed to provide safety and effective operation in drain systems.