How To Repair Cracks on Concrete Floors

Concrete develops chips and cracks over time. These minor problems do not mean there are structural problems. However, when a small chip or crack develops, you can expect it to expand later on. Here is how to repair cracks in your concrete floors before they expand and ruin your floor.

Choose the Right Concrete Filler

The concrete filler is used to seal chips and cracks on concrete. The common types of fillers are self-leveling and concrete foam fillers. It is advisable to use self-leveling filler because the caulk flows inside the crack and seals it permanently. It’s hard to seal a crack using foam filler. This is why in most cases, the crack usually reemerges.


Break down large pieces in the crack using a chisel and hammer. This action is known as keying the crack or chiseling it out. Keying makes the inside or base of the crack larger than the surface. This procedure enables the patching material or filler to seal the crack properly.


Scrub the crack using a wire brush to get rid of dirt, leaves, twigs and any debris. After cleaning the crack, vacuum it thoroughly to remove the tiny particles of dirt. If you apply filler in a crack with dirt or debris, it might not bond well with the crack which means the crack will reappear within a short time.

Apply the Caulk

Fill the crack level with the floor’s surface. Use a spoon or paintbrush to smooth out the crack.  Sprinkle some sand over the filling while it is still wet. The use of sand will help to make the crack lines less visible when the work is complete.

Leave the filler to settle overnight or according to the manufacturer’s direction. After the caulk has cured, inspect the crack to see whether it is firm enough and apply more caulk to achieve the desired strength.


Concrete absorbs stains easily, and the best way to prevent this is through sealing. Use water-based polyurethane product for sealing floors in high traffic areas. If your floor is rough, apply the sealing product with a brush or broom so that the bristles apply the sealer on the rough floor. If your floor is smooth, use a roller to apply the sealer. Polyurethane cures faster and is much easier to use compared to other sealers.

Water-based polyurethane dries faster than most sealers, enabling you to apply another coat a few hours later. For assistance with your concrete repair, talk to a professional.