A sinking slab is always worth fixing, whether it is located in your garage, driveway, patio, basement, sidewalk, or pool area. Cracks are not necessarily the problem. It is when concrete slabs cracks and sinks that it exposes a more serious structural issue. In addition to a structural issue, a sunken concrete slab can also reduce the appearance of your home and pose a safety hazard.
Concrete slabs sink for one of two reasons either the soil beneath the slab may have compressed by the weight of the slab or the ground has eroded underneath the slab causing a void or hole. Some contractors recommend fixing it by demolishing the area that is damaged and pouring new concrete. While this may be appropriate at the time, depending on the concrete itself, it is an expensive process and can take several days to complete. Even so, if it is weak soil that caused the issue, it will just compress again under the weight of the slab. A better option and more effective solution is to support the underlying soil by injecting polyurethane foam into the cavity and ground. Within an hour, the concrete slab is raised by drilling one or more holes about the size of a dime into the existing concrete and injecting the expanding polyurethane foam under the concrete slab. Within minutes the concrete slab is restored to its full weight-bearing function.