Poor soil conditions, including poor compaction and water erosion, cause even the largest of concrete slabs to settle… which creates a dangerous, uneven surface. Driveways and garages, walkways and sidewalks, pool decks and patios are all areas of your home that can be affected by these soil conditions.  The effects can be dangerous… and costly (if someone were to injure themselves) Sentinel Spray Foam (and yes, Concrete Leveling) will help in remedying any tripping hazards and possible liability to the home or business owner. We correct/level uneven concrete surfaces by injecting a 2-part high-density polyurethane foam under the slab using specialized equipment. Using controlled injections, the structural foam then expands and lifts the slab, at the point of compaction, to the desired level. As the structural foam expands under the slab, the pressure from this water-retarding material also displaces any water in those voids, as the path of least resistance, forces foam into voids and compresses/compacts the weak soil underneath. At a compressive strength of 10,000 lbs. per square foot when fully cured, structural polyurethane is strong enough for the toughest of applications.