When homes are built, concrete is often poured on backfilled soil that has been leveled off. This soil is compressed tremendously through mechanical methods, but human methods are not as effective as natural methods. Water enters the poorly compacted soil, slowly washing out loose soil and creating a void under the concrete slab. As the soil washes away, the weight of the concrete causes the slab to settle and crack, causing uneven surfaces, tripping hazards, and pooling water.
To prevent injury on the uneven surface, a sunken, cracked concrete slab needs to be fixed. There are only a few options to solve this problem: destroy and replace the slab, lift and level it, or pour concrete on top of the old slab.
Replacing the concrete is a highly-effective method of fixing the problem. To destroy and remove the old concrete and pour a new concrete slab will take several days before the concrete can be used. Pouring new concrete over, “skim-coating,” the old slab will produce an even surface, but often the new concrete fails to adhere to the old slab. Even worse, the extra weight can cause the slab to sink and crack again. The best solution to a sunken, cracked concrete slab is to lift and level the slab. Homeowners have two options for lifting and leveling a concrete slab: mudjacking and the PolyRenewal™ System.
Mudjacking is an old, outdated method of lifting and leveling concrete. To begin, 3” diameter holes are drilled through the concrete slab. Then, using extremely high pressure, vast amounts of mud are pumped underneath the concrete to fill the void and lift the slab. The extreme pressure can cause mud to erupt violently from the sides of the slab, making a muddy mess of a front yard and driveway. After mud is pumped underneath the slab, the holes are filled in with new concrete, leaving 3” spots of darker concrete. Even worse than unsightly spots on the concrete, mudjacking fails to prevent the problem in the future. The weight of the new mud can cause the loose soil underneath to sink even further, or it can wash out like the soil before. Either way, the concrete may crack even more, making mudjacking a short-term fix at best.
The PolyRenewal™ System permanently lifts and stabilizes concrete slabs. Tiny, 3/8” holes are drilled in the concrete, eight times smaller than the holes needed for mudjacking. Then, a lightweight, high-density, structural grade polyurethane foam is injected underneath the slab. The expansive nature of the polymer allows for an accurate lift of the concrete without the risk of mud erupting on the front yard. The polyurethane foam is so strong that cars can park on the slab after just 15 minutes. Because the foam is extremely lightweight and waterproof, the soil underneath the slab will not sink under extra weight or wash out. Because the PolyRenewal™ System will never degrade, Peak Structural offers a 5-year warranty on PolyRenewal™, unlike mudjacking companies.