Not every slab crack has the same cause.
A concrete slab may develop shrinkage cracks, localized settlement or movement connected to a wider foundation problem. The surface pattern alone is not enough to choose between sealing a crack, addressing water or soil conditions, lifting a nonstructural slab, or providing structural support.
Look beyond the floor finish
- New or changing cracks that continue through finishes or adjoining walls.
- A floor that has developed a noticeable slope or a height difference at a crack.
- Doors binding alongside other movement symptoms.
- Water leaks, erosion, drainage changes or prior foundation repair.
Document the change and mention any plumbing history. Do not cut into a slab or drill exploratory holes without locating embedded utilities and understanding whether the slab contains reinforcing or post-tensioning components.
Assessment before method
An assessment should establish the slab type, accessible foundation condition, movement pattern and relevant water or soil concerns. Floor-level measurements and a review of drainage may be useful. Suspected plumbing leaks may require separate testing. When structural conditions are uncertain, a licensed engineer can help establish an appropriate repair design.
Possible repair approaches
A designed plan may involve foundation underpinning or piers to transfer loads, a targeted repair, or water-management measures. Lifting a settled section of nonstructural flatwork is not the same as stabilizing a load-bearing foundation. Ask why the proposed system suits the building and what it is intended to accomplish.
Before work, clarify access and excavation areas, support locations, utility precautions, permits and restoration. The proposal should state whether the objective is to limit further movement, attempt elevation correction, or both. Cosmetic repairs to finishes may be separate and may need to wait until structural work is complete.
Keep the scope property-specific
Foundation conditions are not established by a neighborhood name or a photograph. For work in the City of Charleston, review the residential foundation repair permit guidance and confirm the required engineering documents. For sunken patios or walks rather than the home’s foundation, see concrete leveling.
Questions about this service
Can a crack simply be filled?
Sometimes a stable, nonstructural crack needs a limited repair, but filling does not correct settlement or an active structural cause. Have the condition evaluated before covering it.
Are slab lifting and foundation underpinning the same?
No. They address different conditions and load paths. Ask exactly which part of the structure is being supported and what evidence supports that approach.