How to Fix Stress Cracks in Concrete

Begin your work before it gets too hot. Heat dries out the concrete patching material too much as it sets, and the cracks might reappear quickly. Ideally, work when the temperature is around 55 degrees Fahrenheit.

Insert a chisel into the bottom of the crack. Begin tapping the chisel with a hammer to slightly widen and deepen the bottom of the crack. Exposing new concrete helps bond the concrete to the patching material. Try to extend the depth of the crack by 1 inch.

Scrape the inside of the crack with a wire brush to help loosen any debris.

Flush the debris out of the crack with a garden hose. Remove as much loose dirt and concrete particles as you can to ensure the patching material bonds well.

Brush a concrete adhesive such as acrylic resin into the crack with a small paintbrush. Coat as much of the inside of the crack as you can; this helps the patching material stay place as it cures. Allow the adhesive to dry for several minutes until it becomes sticky.

Mix some concrete patching material with water according to the directions. It should form a thick paste.

Pour the patching material into the crack. Use a trowel to press the material down into the very bottom of the crack. Continue filling the crack and tamping the patching material down until the crack is completely full. Level the top of the crack with your trowel.

Allow the patching material to dry uncovered for two hours. Cover the crack with wooden boards after two hours to ensure nothing disturbs the patching material as it sets. Keep the boards in place for one week.

Lift the boards once a day to wet the crack down with water. This ensures that the patching material does not dry out as it sets. Remove the boards after one week.