Concrete crack repair is the process of cleaning, filling, and sealing cracks in a slab so they stay stable and do not show through a new coating.
Understanding Concrete Crack Repair
Not all cracks are the same. Hairline shrinkage cracks are usually just cosmetic. Wider cracks, or cracks with height differences between the sides, may mean movement or settlement. The first step is working out whether the crack is dormant or active, because that decides the repair method.
Common Repair Methods
Rigid epoxy or polyurea fillers are used on dormant cracks to bond the sides back together. Epoxy injection can restore strength in deeper cracks. Flexible sealants or joint fillers are used where movement is expected. For wide cracks, installers often chase the crack with a grinder, fill it, and broadcast sand to give the coating something to grip.
Cracks vs. Control Joints
Control joints are planned cuts that let concrete crack in a straight line. They should be honored, not filled solid with rigid material. If a floor cracks beside a joint or at a column, treat it as a crack and repair it. Always follow the coating maker guidance on joints.
Practical Tips for Repairing Concrete Cracks
Grind or route the crack, blow out all dust, and make sure it is dry. Use a repair material that is compatible with the coating system. Let it cure fully before coating. Tell the customer that cracks can still move after the job, and flexible repairs can lower the risk of reflection.
Also Called
Crack filling, Crack patching
