Slab jacking, also known as concrete levelling or concrete releveling, is a technique used to lifts concrete slabs back to their original position. It involves lifting one side of a concrete slab from below, effectively re-leveling it.
This is achieved by injecting a particular filler material underneath the slab. The material fills up the void created due to soil movement or erosion, providing a stable base and allowing the slab to be raised back to its original position.
This technique is often used in cases where concrete slabs have sunk or become uneven over time. A pattern of holes is carefully drilled into the affected slab, and then a mixture, which could range from a mud-like substance to expanding polyurethane foam, is pumped beneath the slab.
The pressure from this injection causes the slab to rise, levelling it with the surrounding area.