The cost of slab foundation repair varies greatly between different methods. Each of the methods of slab foundation repair also varies greatly in the disruption it causes to use of the structure. For example, slab piers are one of the most expensive methods for repairing slab foundations, but also have the lowest ability to lift the slab foundation back in place. The cost of slab foundation repair is often influenced by many factors, such as the location of the structure, the condition of the slab foundation, and the characteristics of the underlying soil, etc.
Foam jacking lifts and raises settled slab foundations by injecting high density polyurethane foam under the slab foundation, where it expands, pushing the slab foundation back up. The lifting is gentle and over a large area at once, which helps to ensure the most complete lifting of all the methods.
Mud jacking lifts and raises settled slab foundations by injecting sand-based grout under the slab foundation. The mechanical force of the pump is what pushes the slab foundation back up. Mud jacking tends to be pretty messy, so it’s best used for unoccupied parts of homes.
Slab piers are pushed or driven into the ground. After that, a hydraulic jack is connected to the top of the pier, to raise the floor. However, because the hydraulic jacks point-load the slab, the slabs tend to crack quickly. Once the slab cracks, further lifting is difficult. Slab piers are very disruptive and very expensive. Concrete Jack installs piers for lifting other parts of foundations, but we believe that the high cost of slab piers and their low success at lifting slabs makes them unattractive enough that we do not install them (we recommend foam jacking for slab foundation lifting in all but the most unusual circumstances). Both push piers and helical piers may be used for slab pier installation. Helical piers do not require applying any loads to the slab during installation, so tend to reduce chances of the slab cracking. After any slab pier installation, it is important to fill the voids that already exist under the floor, or develop as a result of lifting, to help prevent deterioration of the slab.
Replacement is the most expensive of the slab foundation repair methods. It is also incredibly disruptive, and can cause problems with other parts of the structure if they are not property braced while the concrete is removed and replaced.