What type of inspection must occur after trenches are excavated?

The inspection that must occur after trenches are excavated is an underground inspection. This type of inspection is critical because it ensures that all underground plumbing installations comply with the relevant codes and standards before they are covered up. The underground inspection typically checks for proper installation and alignment of pipe fittings, verifies that the materials meet the specifications, and ensures that the trenches are properly sloped for drainage.

Conducting this inspection is vital for preventing issues that could arise from improper materials or installation, which would otherwise be difficult to assess once the trench is filled. The underground inspection helps maintain system integrity and can identify potential problems early in the construction process.

Other types of inspections like rough-in inspections occur later in the process when the plumbing is partially installed but above ground, final inspections take place when the project is complete and ready for use, and the term major inspection is not standard in plumbing inspection terminology as per the International Plumbing Code.