Spray foam injection to lift your sidewalks is precise, cost-efficient, and effective. Our spray foam technique for concrete leveling uses the concrete slab itself to deliver polyfoam. It will raise concrete and fill voids.    To start concrete leveling, our team will drill a hole the size of a nickel through the slab into the subgrade. The foam will expand in seconds within seconds, compressing any loose soil and raising the concrete. Concrete leveling using polyurethane foam is done with incremental injections until the whole area is raised.