Concrete is a conglomerate material made out from cement, gravel and water. It is a great material for making a concrete retaining wall. Due to the forces of time and weathering, it is not uncommon for the material to crack.
Small cracks are easily remedied and fairly harmless but larger cracks affect the integrity of the overall structure and should be repaired promptly with care.
Before repairing a crack it is important to protect yourself from dust and debris by wearing a mask that covers both your nose and mouth. Goggles should also be worn to protect your eyes during the process of crack maintenance.
Locate the largest cracks in the concrete and undercut them about and inch and a half using a hammer and chisel. Use your hammer and chisel to remove enough material below the crack for the patch you install to be effective and stay in place.
Use a stiff wire brush to clean away all of the dust and debris created where you chiseled below the crack. Make sure that the area is as clean as possible to ensure complete adhesion of the future concrete patch. The hole should be free of dust and completely cleaned before moving on to the next step.
Warning: The final steps involve mixing and applying fresh concrete to the crack. You may want to wear disposable gloves during this time so you can use your hands and you don’t dry out your skin.
Obtain ready mix concrete and a container that is suitable for mixing concrete. Remember that concrete can be easily washed out of a container while it is wet, however, once it is dry concrete is extremely difficult to remove.
Mix a small amount of ready mix concrete with the appropriate proportion of water. Use your hands or a trowel to cover the inside of the crack with the cement mixture about 1/2 inch thick.
If you’re using your hands you can use your fingertips to physically press the concrete into the deepest crevices of the crack in the wall. Smooth out the indentations made by your fingerprints with a trowel to leave the surface smooth and level.
Remember: during this initial application of concrete you are not completely filling the crack. Instead, you are creating a solid foundation on which the larger concrete patch can adhere itself to.
Now, mix the remainder of your ready mix concrete with the appropriate amount of water and blend thoroughly. This concrete must be uniform and flawless because it is going to form a patch which must withstand the effects of time and weather.
Fill the remainder of the crack and hole with the concrete; making sure not to leave any air bubbles or gaps. Wipe away any excess concrete with a disposable cloth and smooth out the fresh patch with your trowel.
For the next four or five days, revisit the site of the crack and mist the fresh patch of concrete with water. The water will keep the concrete moist while it dries which strengthens it and prevents it from cracking again.