Garage floor cracking

Cracks in a concrete garage floor are extremely common — nearly every garage slab develops them eventually due to concrete's natural shrinkage as it cures, thermal expansion and contraction, soil settlement beneath the slab, and the weight of vehicles. Hairline cracks (under ⅛ inch) are cosmetic and can be sealed with flexible concrete caulk to prevent moisture infiltration. Wider cracks (¼ inch or more), cracks that are uneven (one side higher than the other), or cracks that grow over time may indicate structural settlement or poor drainage underneath the slab. A handyman can repair cosmetic cracks for $100–$300. Structural issues require a concrete contractor — mudjacking or polyurethane foam injection to level a settled slab runs $500–$1,500, while full slab replacement costs $3,000–$8,000.