What is the difference between mudjacking and polyjacking?

Mudjacking pumps a cement-sand slurry beneath the slab to lift it, while polyjacking uses expanding polyurethane foam. Polyurethane foam is lighter, cures in 15 minutes versus 24 to 48 hours for mudjacking, and does not add weight that could cause further settlement. Mudjacking uses larger drill holes and is typically used for heavier commercial applications.