Repairing Cracks in a Concrete Driveway

One of our first impressions driving up to a home is the driveway. Like anything else, concrete driveways need to be maintained.

Concrete is a very durable building material and an excellent material with which to pour a driveway. Basically, concrete is a mixture of sand, aggregate, water, and cement. The cement is the base in which the sand is embedded and glued together with the help of water.

While we all think of concrete as being very strong, it can be damaged by freezing water, standing water, excessive heat, expansion and contraction of the sand or aggregate from which it is made, shifting of the ground, tree roots, overloading, and even certain kinds of bacteria. Its strength is compression, but it is weaker in tensile strength (pulling) so things like this can easily cause it to crack. Fortunately, repairing most concrete driveway cracks today is a relatively inexpensive, straightforward do-it-yourself project.

Resurfacing Concrete

Asphalt driveways have always been popular because they are much less expensive than concrete and easily repaired. One needs only to scratch out the cracks, clean and scour the surface to aid in bonding, and then pour a thin layer of asphalt on the surface. Compress and leave to cure for a few days and the driveway looks good as new.

Years ago, worn concrete driveways were typically replaced and required a very strong back because the old driveway needed to be jack-hammered and the old concrete carted away. Today, there are acrylics and polymer-based cement mixtures that can be used to resurface your old driveway more easily than resurfacing asphalt. One manufacturer makes a driveway repair product with Portland cement and polymers. This is mixed with water and can be simply applied with a squeegee or broom.

Caution: it cures very quickly. Once you add water, you have but 30 minutes to apply a thin even coating before it sets up. That said, it does a great job and truly rejuvenates the driveway.

Patching Concrete Cracks

Clearly not all repairs require resurfacing the entire driveway. Driveway cracks come in a host of sizes and shapes—from hairline cracks to more significant fissures. Regardless of the size of the crack, there a few simple steps that should be taken before fixing the crack.

Clean It - The crack should be cleaned thoroughly to ensure proper bonding between the old surface and the repair material. Cleaning entails removing loose pieces of the old concrete with a chisel or equivalent tool and then removing the remaining debris with a wire brush and sweeping it away.

Fill It - The crack can then be repaired and filled with something as simple as concrete caulking for hairline cracks or concrete sealer designed to fill larger cracks. You should also use a trowel to compress the material firmly into the crack.

For an aggregate driveway, you will want to pour sand over the concrete patch and roll over it with a somewhat heavy object.

Let It Cure - Once the patch is in place, it has to be allowed to dry and cure before you park a car on it. Curing is not the same as drying. Pourable concrete is easier to work with than the polymer coatings, not only because you are working on a much smaller area than you would be if resurfacing an entire driveway, but because they typically dry more slowly, allowing you time to work, plus many patching products are designed to cure quickly, to reduce the wait after you're done. Obviously, referring to the manufacturer’s instructions will alleviate any difficulties.

If you've used sand on the crack of an aggregate driveway, sweep or wash away the excess after the curing process has finished.

Seal It - Concrete is porous and water is one of the major culprits that can do damage to your driveway. To help minimize water damage, it is always a good idea to regularly apply high-quality water sealer.

Moral of the Story

Repairing cracks in a concrete driveway is a simple project for most DIYers. Whether or not your driveway needs a complete overhaul or just the repair of small weathering cracks, there are products available that make the job easy.