Under what condition is tight sheeting required in excavation work?

Tight sheeting is required in excavation work primarily when the soil is submerged or when water is seeping into the excavation site. This is crucial because the presence of water can destabilize the surrounding soil, increasing the risk of soil collapse or making the excavation unsafe for workers. Tight sheeting refers to the use of solid panels or sheeting materials that are installed to prevent water from entering the excavation and also to provide additional support to the surrounding soil. By utilizing tight sheeting in conditions where water is present, it helps maintain the integrity of the excavation and safeguards the safety of workers involved in the operation.