What is the maximum permissible length of a drainage run without a cleanout?

The maximum permissible length of a drainage run without a cleanout is 30 feet. This standard is important to ensure that maintenance and inspection of the drainage system can be performed effectively. A cleanout allows easy access to the drainage pipes for clearing obstructions, conducting inspections, and performing maintenance.

If a drainage run exceeds 30 feet without a cleanout, it becomes increasingly difficult to access the interior of the pipes for these purposes. This distance is generally established based on practical considerations to balance accessibility with the layout of drainage systems within buildings. Access to cleanouts ensures that blockages can be addressed quickly without requiring extensive effort or invasive procedures, which could compromise the integrity of the drainage system.

The other choices represent lengths that exceed the established standard and would not comply with typical plumbing codes, stressing the importance of adhering to established guidelines for maintaining effective and maintainable drainage systems.