A small 2” hole is drilled in the slab.
A nozzle is secured to the hole to carry slurry set to the proper consistency. The voids are filled and the slab is raised to acceptable tolerances. The small hole is patched and the room is restored and problem resolved.
A slurry of mud and cement is pumped under the slab (depending on the amount of lift) to fill the voids created by raising the slab. All pier areas are then backfilled with sand and top soil and plants are replaced.
Any concrete break-outs are patched smooth with new concrete and the entire area is given final clean-up.