Concrete Patio Sinking or Settling — Haarlem, Noord-Holland

A concrete patio that has sunk creates trip hazards at the step-down from the house, collects standing water against the foundation wall, and can crack along stress lines as the slab tilts. Settling usually happens when the fill soil beneath the slab compacts over time, when downspouts wash soil out from under the edges, or when tree roots decompose and leave voids. A concrete mason can lift the sunken sections using mudjacking or polyurethane slab-jacking, seal the resulting joints, reroute drainage away from the patio, and fill any underlying voids to prevent repeat settling.