Foundation Pro uses pressurized, structural Polyurethane that expands to high density in order to help stabilize soils, fill voids and/or raise concrete slabs. A 5/8-inch port is drilled into the slab and a two-part polymer solution is injected under the slab. The curing process usually takes only 2-4 hours. The injection ports are patched with mortar or grout upon completion. This method is used to raise interior residential and commercial slabs, concrete porches, driveways, pool decks, sidewalks and more!