Minor Concrete Crack Repair
Minor cracks are those which are not more than 3 millimeters in size. To begin with, beat the cracked site gently with a chisel and hammer or simply with a screw driver to detach any loose flakes of concrete. After removing the chips, rub a wire brush on the area to clean up all dust and debris. Then moisten the old concrete thoroughly with water for few hours, using a garden hose. This is done so that the concrete does not extract water from the patching grout and make it dry. Make sure that the concrete is damp, but there should not be any standing water on it. Purchase a patching compound from the local hardware stores and prepare a thick paste with water, following the directions given by the manufacturers. Add a latex additive to it in order to improve its strength and flexibility for natural expansion. Apply the compound over the crack with the help of a small putty knife. Smoothen up the surface of the crack properly before it gets hardened. Let the repaired patch dry for two-three hours and then cover it up with a plastic sheet. Keep it covered for the next 5 days so that it dries up completely, before you start using it for walking or driving.
Major Concrete Crack Repair
When the size of the crack varies in between 3 millimeters and 6 millimeters, then we consider it as a large crack. Here the preparation work is the same as that of a minor crack where the loose debris from the concrete has to be eliminated first. It is followed by cleaning and moistening of the concrete surface. Prepare a patching mortar by mixing up one part of Portland cement and three parts of fine sand with water. You can also add some latex additive to make it more flexible. Fill up the cracked area completely with the prepared concrete mixture. You have to apply it several times before the crack gets covered up. Smoothen up the rough edges with a wooden float. Then use a metal trowel to give it a better finish. Wait for two hours before you cover up the area with a plastic board. You should apply water on the patched area, once a day, to improve bonding of the concrete. Continue this for the next 7 days, and then you can start using the concrete.
The moment you discover the crack you must take prompt action to fix it. If you neglect it for long, it will develop into a much deeper crack and you may find it difficult to manage the repair work. On an average, concrete repair cost may vary in between $400 and $800 if you are hiring a professional. When you are doing it yourself, it can be done at a much lower cost and thus, you will be able to save money.