Most concrete raising jobs will take a few hours —start to finish— and your concrete will be ready for use immediately upon completion! Polyurethane
concrete raising uses a foam material that is injected under the slab. When the components of this material are mixed, a reaction causes the material to expand.  This expanded foam fills any voids beneath the slab and raises the concrete. This material will never lose density, is permanent and weighs only about 2 lbs. Per cubic foot.