Get matched with top excavation pros in White Hall, IL

Most residential basements are 8 to 10 feet deep. You can dig deeper depending on building codes, but it does become more difficult. You’ll likely need to install stronger foundation walls and additional supports to handle the increased load. Depending on the water table, you may also need a water management system. Clay soil can support a deeper foundation than sandy soil. A structural engineer will be able to tell you the maximum, feasible depth.

A trench that is less than 5 feet deep often doesn't require a protective system. Most residential trenches will not go this deep (the typical residential drainage trench is just 18 inches deep). In the event that an excavator needs to dig more than 5 feet beneath the surface, a protective system is required unless the excavation is in entirely stable rock.

A perc test can take anywhere from one to eight hours to complete. The total time depends on factors like the amount of excavation required, the depth and width of the holes, and whether multiple test holes are needed. For a single hole, the process of filling it with water and monitoring the drainage rate usually takes less than an hour. Professionals can often complete the entire test in a single day. While it's possible to get results the same day, some companies may take a few days to provide the official report.

Professional installers often include a deep layer of crushed gravel under permeable pavers to allow more runoff to soak through into the soil below. Many installations will include multiple layers of gravel, with coarser aggregate at the base and finer aggregate that sits on top of that bottom layer. Above the gravel, you’ll often find coarse sand that helps reduce paver shifting over time. Some permeable paver designs include a water collection system set into the gravel layer to route runoff to a safe area for disposal.