Over time, the concrete slab that makes up your driveway can settle, causing it to crack or allow water to puddle in the low areas. There is a solution to restore the driveway through concrete lifting that eliminates the need to demolish and repour the concrete.
Concrete lifting allows a contractor to use a high-density self-expanding polyurethane foam to raise concrete slabs that have settled back to their original level. The foam must be injected under the slab at a controlled rate, so it is vital to hire a contractor with experience lifting concrete for the job.
In some situations, the ground below the slab has eroded, but the foam will replace that soil, and once it has cured, it is strong enough to support the weight of cars on the driveway without any problem. If the concrete slab is already badly cracked, you may not be able to use concrete raising services to fix it, but a contractor can look over the slab and let you know how to best deal with your situation.
Raising The Slab
When the concrete lifting contractor is ready to raise the concrete, they will start with drilling holes through the slab. This process takes some patience, and pushing the drill too hard can cause the concrete to crack or break.
Once the holes are in the concrete, the foam is carefully injected under the concrete slab in small amounts. As the foam begins to expand, the concrete will begin to rise back into position. The concrete leveling contractor will continue to adjust the level by adding more foam until the concrete is level.
The polyurethane foam used under the concrete is water-resistant and durable enough to support the driveway for a few years. If the concrete begins to sink again before that, it may mean you have water running under the concrete and eroding the base. The solution would require pulling up the concrete, adding drainage, then repouring the concrete driveway.
Once all the foam is in place, the contractor will fill the holes in the concrete with hydraulic cement so the surface is smooth and water can not get down the holes and under the concrete. The cement will dry in a few hours and cure completely in about twenty-four hours. The spots may show on the driveway surface, but the slab will be level, and water should run off properly once the repair is complete.
Concrete Leveling Cost
If you are considering concrete leveling for your driveway or another concrete slab, you will need to have a contractor come and inspect the job to give you an exact price. Depending on the size of your driveway, the cost of raising it ranges from $750 to $850.