Which condition mandates the lining of an excavation for gas appliance installation?

The requirement to line an excavation for gas appliance installation primarily pertains to excavation depth and specific standards set to ensure safety and compliance with building codes. When the depth of the excavation exceeds certain measurements, it becomes critical to prevent soil collapse, protect the integrity of the surrounding area, and ensure the safety of workers.

In this context, a depth exceeding 12 inches is a relevant threshold. Excavations of this depth may lead to increased risks of cave-ins, especially in unstable soil conditions. Lining the excavation provides additional support, maintaining safety protocols for both the installation process and the long-term stability of the appliance setup.

Understanding soil characteristics can also play a role in excavation practices, but the specific mandate for lining is more directly tied to the dimensions of the excavation itself. Other factors, such as appliance size, typically do not dictate the requirement for excavation lining but might influence other installation aspects. Therefore, making it clear that a depth exceeding 12 inches necessitates additional precautions, such as lining, is crucial for safe and compliant gas appliance installation.