When should underground inspections be conducted?

Underground inspections are an essential part of ensuring the integrity and safety of plumbing systems. Conducting these inspections after trenches are excavated and before backfill is critical because it allows for a thorough examination of the piping and fittings laid in the trenches. This timing ensures that any potential issues, such as improper installation or damage to the piping, can be identified and rectified before the trench is filled with backfill material.

If inspections were conducted before any piping was installed or after backfill is completed, it would not be possible to verify the installation's quality and compliance with the relevant plumbing codes. Conducting inspections during the installation of fixtures also does not pertain directly to the underground systems, as it doesn’t provide the opportunity to evaluate the underground components that may be critical to the overall functionality of the plumbing system. Thus, performing inspections after excavation and before backfilling is key to maintaining the system's integrity and ensuring compliance with safe plumbing practices.