What is the recommended practice for the arrangement of drainage pipes in a trench?

The recommended practice for the arrangement of drainage pipes in a trench is that they must be fully supported. This ensures the proper functioning of the drainage system by maintaining the intended alignment and slope of the pipes, which is crucial for effective water flow and to prevent blockages. Supporting the pipes helps to prevent any sagging or shifting that could occur if the pipes are not adequately supported, leading to potential issues such as improper drainage or damage to the pipes.

Additionally, ensuring that the pipes are fully supported contributes to their durability and stability over time, reducing the risk of future repairs or maintenance caused by improperly installed drainage systems. This practice aligns with various plumbing codes and standards that prioritize safe and effective installation techniques in drainage systems.