How To Repair Concrete Floors (Large Cracks)

Worker evening concrete on site
Cultura RM Exclusive/Peter Muller

Tough as it is, concrete tends to develop small cracks and chips. Minor problems like this generally do not indicate any structural problems, but it is best to tend to concrete repair of cracks as soon as possible. Once a small crack or chip appears, future wear and tear will only cause it to expand. Here's how to fill a crack 1/4- to 1/2-inch wide. For smaller cracks, follow these instructions.

Difficulty: Easy

Time Required: 1-2 hours

Here's How:

  1. With a wire brush, clean the crack. Sweep away any loose debris, then vacuum the crack. If grease, oil or dirt remains in or near the crack, clean it thoroughly.
  2. With a cold chisel and large hammer, undercut the edges of the crack. This will help hold the patch in place. Be sure to wear eye protection.
  3. With a small paint brush, coat the crack surface with concrete bonding adhesive. Allow the adhesive to dry completely.
  4. Mix a suitable amount of sand mix with water as instructed on the bag. (Sand mix is one variety of dried concrete products sold in bags on home stores.)
  5. With a trowel, fill the crack thoroughly with the mixture. Smooth and level the surface.
  6. Allow the patch to cure undisturbed as instructed on the bag.

What You Need:

  • Wire brush
  • Vacuum cleaner or Shop-Vac
  • Cold chisel
  • Hammer
  • Safety glasses
  • Concrete bonding adhesive
  • Paint brush
  • Sand mix
  • Trowel