Polyurethane foam injection and mudjacking are both methods for raising and stabilizing sunken concrete slabs, but they differ significantly in material, invasiveness, and durability. Polyurethane foam injection, also known as polyjacking, is a newer, less invasive process that uses a lightweight expanding foam. Mudjacking is the traditional method, using a heavy, cement-based slurry.  Comparison at a glance: Before deciding on how you want your concrete raised, it's importan