What is the term for testing the stability of roofs constructed with lightweight trusses?

The correct term for testing the stability of roofs constructed with lightweight trusses is "sounding." This method involves striking the roof surface with a tool and listening for the quality of the sound produced. A solid, stable roof will emit a different sound compared to one that may be compromised or unstable. Sounding helps firefighters assess the condition of the roof while ensuring their safety when working in potentially hazardous environments. This practice is particularly crucial with lightweight trusses, which can fail rapidly when exposed to heat, making early detection of instability essential to maintaining safety during firefighting operations.

The other options do not specifically refer to this method of assessing structural integrity in the context of roofs.