Polyurethane concrete raising is a repair method that injects expanding polyurethane foam through small holes in a sunken concrete slab to lift it back to level, fill the voids beneath it, and stabilize the underlying soil.
In depth
The process begins by drilling holes about the size of a dime (5/8 inch) through the settled slab and installing injection ports. A two-part polymer is then injected through those ports, flowing into the space between the slab and its failed subbase. The material reacts within seconds, expands, and forms a rigid structural foam that fills voids while gently raising the concrete to its original elevation.
Because the cured foam weighs only about 2 to 4 pounds per cubic foot, versus more than 100 pounds per cubic foot for mudjacking slurry, it lifts the slab without adding meaningful weight to soil that is already struggling to carry the load. The foam is water-resistant, will not wash out or shrink, and cures in roughly 15 minutes, so the surface is ready for full use almost immediately.
How Acme applies it. Acme Concrete Raising & Repair was the first Chicagoland contractor to specialize primarily in polyurethane concrete raising, and injection is all the company does. Its Smart Lift System handles everything from residential sidewalks to 42-mile highway runs on the I-294 Tollway.
Related terms: Foamjection, Polyjacking, Mudjacking, Concrete Leveling, Polyurethane Foam
Frequently asked questions
How long does polyurethane concrete raising last?
The cured foam is synthetic, so it will not break down, shrink, or wash out the way mudjacking slurry can, and it is engineered to perform for decades. Longevity still depends on managing water and drainage around the slab so the soil does not erode again.
How soon can I use the concrete after it is raised?
The lifting foam cures in about 15 minutes, so driveways, sidewalks, and floors are typically ready for full, unrestricted use as soon as the crew finishes.