What does the term "lagging" refer to in excavation practices?

The term "lagging" in excavation practices refers specifically to the support boards that are placed along the sides of an excavation. These boards are typically used in conjunction with other supports, like sheeting or braces, to prevent the sides of the excavation from collapsing. The lagging serves as a crucial element to stabilize the walls and protect workers by providing additional support and creating a safe working environment.

In excavation, particularly in trenching or in the construction of deep excavations, lagging can be critical to manage soil pressures and prevent accidents. The materials used for lagging are often wooden boards or planks, but they can also be made from other materials depending on the specific requirements of the excavation site.

While temporary support for tunnels may seem related, it does not precisely match the specific definition of lagging as it is used to refer to the direct side support. Likewise, materials used for drainage and sloped support for excavation sides do not accurately define the primary function of lagging. It is the direct application of lagging that provides necessary structural stability within excavated areas.