Concrete is tough, but it can crack because of settling, moisture, or extreme temperatures. For narrow cracks, less than about 1/8 inch wide, simply buy a concrete patch sold in a caulking tube and apply it according to the label directions. Wider cracks require a little more work to prevent them from reoccurring.

1) Wearing safety glasses, use a hammer and a cold chisel to deepen the crack to at least 1 inch. Undercut the sides of the crack so the patching material will grip.

2) Brush away loose debris with a wire brush, and then sweep or vacuum the crack to remove dust.

3) Mix a patching compound specifically made for concrete, following the label instructions.

4) Trowel the patching compound generously into the crack, overfilling the crack slightly. Skim off excess with the trowel.

5) Once the patch has set, smooth it out with your trowel so that it's flush with the surface.

6) Sprinkle the patch lightly with water several times a day for about a week to help it cure properly.

7) Apply a concrete sealer for lasting protection.