It is best to repair wide cracks in concrete with a concrete patching compound that will fill and seal the cracks. Find a concrete patching compound that has a texture similar to the concrete you’re repairing. Smaller cracks that are less than ¼ inch wide can be repaired with a concrete caulk.
Concrete patching compounds are created using a mixture of water and the powdery/grainy compound. They are available in various textures from smooth to grainy to blend more naturally with the rest of the concrete. However, the colour of the freshly repaired concrete will look brand new and most likely will not match the old concrete. It generally takes a few seasons for new concrete crack repair to blend in with the existing concrete.
Repairing cracks in your concrete
Before you begin repairing wide cracks in your concrete, you should always do an assessment of any cracks throughout your home. Cracks throughout your home can oftentimes be indicators of a more serious issue. It is a good idea to monitor the cracks for a short period of time before deciding to repair them.
Things to look out for include:
- The location of the crack
- Size of the cracks
- Direction of the cracks traveling
- If the crack has worsened over time
If your home is forming cracks due to structural damage, you won’t want to repair them now. Instead, you will need to call a professional to assess the condition of your foundation and check for structural damage.
Cracks that could indicate structural damage look like:
- Large cracks more than ½ inch wide
- Cracks in your home’s foundation or stucco
- Cracks your floor slab
- Diagonal cracks in drywall coming from corners of doors and windows
- Cracks that expand or lengthen over time
How to repair wide cracks in concrete
To fix a wide crack in concrete, you need to first remove any loose material or debris. To do this, use a hammer and chisel to chip away at the sides of the crack to form a “V” shape. This step will also ensure that the concrete compound bonds securely with the concrete.
- Chisel the crack to dislodge any loose debris from the concrete.
- Remove all the debris and brush away sand and dust from the area. If you wash with water, sponge up any pooling water.
- Mix the concrete patching compound by following the manufacturer’s directions.
- Fill the crack by using a trowel to scoop and disperse the compound into the crack. Poke the compound with the trowel to remove air pockets and work the compound deep into the void.
- Smooth the surface of the compound and sponge away any excess surrounding the crack to feather it.
- Let the compound cure as directed and finish off with a concrete sealant to maintain your concrete.
How to repair narrow concrete cracks
To fix a narrow crack in your concrete, you will need to use masonry concrete crack filler that comes in a cartridge to be used in a caulking gun. Narrow cracks can be deep enough to cut through the entire concrete slab so it is a good idea to stuff a foam backer rod into the crack.
- Stuff some foam backer rod, slightly wider than the crack gap, into the crack with a screwdriver to create a solid base for the repair material.
- Fill the crack with the repair material, following the manufacturer’s directions.
