Concrete Leveling – Dog Kennel – Kearney, NE The bubble in this level shows just how much this slab has moved over time. Inserting the injection port into the concrete slab after drilling the hole. Equipment used to inject the foam under the concrete slab. Technicians injecting foam under the surface of the concrete slab. Finished and leveled concrete slab with a perfecty level outcome. Concrete slab after the foam has been injected and the slab raised.