Engineered to spec. Timed to the pour.

Metro Detroit foundations are excavated below the frost line to protect against frost heave. Michigan building code and most local jurisdictions require foundations at least 42 inches below finished grade for residential, though many engineers specify 48 inches for additional margin. Full basements typically excavate 8 to 10 feet below grade for finished ceiling height plus slab, footing, and vapor barrier allowance. Crawl space foundations run 4 to 5 feet deep. Commercial foundations depend entirely on structural engineering and can run anywhere from 5 feet for shallow spread footings to 20+ feet for deep foundations on poor soils.

Metro Detroit soil varies significantly by county. Much of Wayne and Oakland counties sit on dense clay that holds walls well during excavation but can require longer drying time before pour and careful compaction of backfill. Parts of Macomb and northern Oakland have sandier soils that drain better but need more attention to sidewall stability during the dig. High water table areas near the Rouge River, Clinton River, and Lake St. Clair shoreline often require dewatering during excavation. A soil bore or geotechnical report is recommended for any foundation project, particularly on new construction or when replacing a failed foundation.

OSHA Subpart P governs excavation safety and requires protective systems for any trench over 5 feet deep that workers enter. Options include benching (cutting soil back in steps), sloping (laying back sidewalls at a safe angle based on soil type), shoring (installing hydraulic or screw-jack supports), or trench boxes and sheet piling for deeper or unstable conditions. Most residential foundation excavations under 8 feet can be safely sloped on stable soil. Deeper commercial foundations and any excavation on poor soil or next to existing structures typically require engineered shoring. Liora Works follows OSHA competent person requirements on every excavation over 5 feet.

Concrete pour should happen as soon as practical after excavation is complete, typically within 3 to 7 days. Longer gaps expose the excavation to weather, rain accumulation, and potential sidewall degradation. Coordination between excavation and concrete subs is critical. Liora Works schedules foundation excavations with target completion dates aligned to the general contractor's concrete schedule, and we're on-site for any touch-up or adjustment work the concrete crew needs when they arrive. Open excavations sitting for weeks cost more to restore before pour than they save on the original schedule.

Residential foundation excavation costs depend on excavation volume, depth, soil conditions, access, and whether dewatering or shoring is required. A standard 2,000 square foot basement excavation at 9 feet deep on cooperative soil typically runs $8,000 to $16,000 for excavation work alone. Crawl space foundations run $4,000 to $9,000. Footing-only excavation for additions runs $2,000 to $6,000. Commercial foundation excavation is quoted per project based on structural drawings and geotechnical reports. Dewatering, shoring, or contaminated soil disposal add costs that are quoted as separate line items so they're not hidden in the base price.

Liora Works performs foundation excavation as a subcontractor to the general contractor or project owner on most new construction and addition projects. We take the plans, coordinate with concrete and structural engineers, execute the excavation scope, and hand off a dig that's ready for footing installation and pour. On residential rebuilds and tear-down-rebuild projects where we're also handling demolition, the whole sequence can run under one contract from teardown through foundation-ready excavation. Coordination with other trades (concrete, waterproofing, plumbing rough-in under slab) is standard scope included on every project.