How is concrete raised back up?

Concrete can sink or settle for several reasons. If the original concrete was installed on dirt that had not been compacted properly, the slab will start to settle within a few years. Soil erosion is another big contributor. The earth also naturally settles over time so if the slab is over seven to ten years old, it may be the natural progression of things. In any case, once the concrete does start to tilt or sink it can cause walking hazards, unwanted water runoff, or major foundation issues.

The entire process is fairly simple. First, small holes are drilled into the concrete slab to be lifted. Concrete Grout is then pumped into these holes under pressure, filling any gaps under the slab. When the gaps are filled, the grout becomes pressurized, and raises the slab hydraulically to the necessary height. In the final step, the holes that were originally drilled are then filled with a concrete mixture.