At what depth must a protective system be used unless the excavation is made entirely in stable rock?

A protective system must be utilized in excavations deeper than 5 feet unless the excavation is made entirely in stable rock. This safety requirement helps prevent cave-ins, which can pose serious hazards to workers. When an excavation reaches this depth, the potential for soil instability increases, and the risk of collapse becomes significant.

Protective systems, such as trench boxes or shoring, are designed to provide support and prevent soil from falling into the excavation, ensuring worker safety during operations. The regulation is rooted in the understanding of soil mechanics and the behavior of materials under load, and it sets the threshold at 5 feet to proactively mitigate risks associated with deeper excavations. Thus, adherence to this requirement is crucial for maintaining a safe work environment in construction and excavation activities.