Wear gloves, safety glasses, long sleeves, and long pants when drilling, hammering, or chiseling concrete.
Patching Cracks in Concrete
The technique for patching cracks will depend on the size of the crack.
- Remove any loose debris from the crack and surrounding area with a wire brush and broom.
- Narrow cracks can be filled with a masonry crack filler that comes in a cartridge designed to be used in a caulking gun. Or you can fill the cracks with a vinyl concrete patching compound applied and smoothed with a putty knife. Vinyl concrete patching compound does not require the use of a bonding agent.
- Use a small sledgehammer and chisel to undercut the edges of the crack. Undercutting the crack makes it wider at the base than at the surface, providing a mechanical method of "keying" the patch in place for a more secure and permanent repair.
- Clean the area in and around the crack with a wire brush and broom. Wash the area with a stream of water.
- Mix vinyl patching compound as directed by the manufacturer and trowel the compound into the cracks. Tamp the mixture to remove air pockets. If you use patching mortar instead of vinyl patching compound, either mix it with bonding agent instead of water or coat the edges of the surface to be repaired with bonding agent.
- Smooth the mixture with the trowel.
- When the patch has set (see manufacturer's instructions for the patch compound you are using), smooth or brush the surface to match the surrounding area.
Simple Concrete Repairs
Prepare the Area
Make a Form
Make the Repair
How to Repair Concrete Slabs or Walks
Remove the Damaged Concrete
Clean Up the Area
Make the Form
Making the Pour
Important Tip: Tap the sides of the forms to settle the concrete and to minimize bubbles.
Time to Trowel
Match the Look
Note: Keep off the patched area until it has had time to cure according to the manufacturer's instructions. A slow cure is best for concrete. For this reason, the manufacturer may recommend that you mist the fresh concrete with water and cover it with plastic for at least three or four days.
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