The foam itself is orange-yellow in color before curing but is injected entirely beneath the slab surface and is not visible after injection. The only visible evidence of the process is the small patched port holes in the slab filled with cement mortar. The concrete surface itself is not treated, coated, or altered in any way during the injection process.

There is no practical upper limit on slab area for foam injection and commercial warehouse floors covering thousands of square feet are routinely leveled with this method. Larger slabs require more injection ports and more material volume but the process scales linearly. Technicians can address different zones of a large slab independently with controlled lift per port.

Foam injection fills the existing void and lifts the slab, but if the root cause such as poor drainage or a leaking pipe is not corrected, new voids can form over time. Scaldino includes a drainage assessment with every leveling job and identifies conditions that could cause re-settlement. Addressing the root cause is part of delivering a lasting result.

Technicians perform a tap test by striking the slab surface with a hammer and listening for the hollow sound that indicates a void beneath. Ground-penetrating radar can be used for larger commercial slabs or where void locations are uncertain. A slab sitting over a void will also often flex slightly underfoot or show stress cracks radiating from the void boundary.

The cured polyurethane foam is chemically stable, non-leaching, and classified as an inert solid. It does not release chemicals into soil or groundwater after curing. The liquid components are handled only by trained technicians following standard chemical safety protocols. Once injected and cured the material presents no environmental risk and is not regulated as hazardous waste.

The technician tap-tests the slab to locate voids then drills 5/8-inch holes at strategic points over the sunken area. Two-part polyurethane foam is injected through each port and the components mix at the tip, react immediately, and expand beneath the slab to fill voids and generate upward pressure. The technician monitors slab movement and stops injection when the target elevation is reached. Ports are patched with hydraulic cement and the area is ready for use in 15 minutes.

Polyurethane foam is water-resistant, does not erode, and typically lasts 10 to 20 years or longer when the underlying drainage issue is corrected. Unlike mudjacking slurry, the foam does not wash out or compress over time. Results depend on addressing the root cause of settlement, such as improper grading or downspout discharge near the slab.

Mudjacking pumps a cement-sand slurry beneath the slab to lift it, while polyjacking uses expanding polyurethane foam. Polyurethane foam is lighter, cures in 15 minutes versus 24 to 48 hours for mudjacking, and does not add weight that could cause further settlement. Mudjacking uses larger drill holes and is typically used for heavier commercial applications.

Concrete leveling typically costs 50 to 75 percent less than full replacement by eliminating demolition, disposal, new pours, and extended curing time. For slabs that are structurally sound but have settled, leveling is almost always the more cost-effective solution. Replacement is only warranted when the concrete itself has deteriorated beyond repair.

Most residential concrete leveling jobs are completed in one to three hours depending on the number of slabs and severity of settlement. Polyurethane foam injection cures in 15 minutes, allowing same-day use. Mudjacking requires 24 to 48 hours before the area can be driven on.