Concrete Leveling & Mudjacking
Signs of a Problem
When the soil supporting a concrete slab settles or washes away, the concrete may crack and sink. Unlevel concrete is relatively easy to see; identifying areas that could crack in the future may require a keener eye.
After especially wet or dry weather, look around your property for any unsupported areas of concrete, such as the edges of the driveway, sidewalk, walkway, patio, steps, and foundation. Take note of any voids or gaps in the surrounding soil, even if they’re small. It’s important to have unlevel or sinking areas repaired promptly since these are problems that will only worsen (and become more costly to correct) with time.
Causes of Settlement
Incorrect grading near your home’s foundation, clogged gutters, short downspouts, and other drainage issues can all cause the soil supporting the concrete around your home to wash away or settle unevenly. Soil washout can leave voids underneath concrete surfaces, creating the ideal environment for the unsupported slab to sink and crack over time.
Extended periods of dry weather can also be problematic for concrete. Some areas of the country are rich in expansive clay soil. This type of soil expands in wet conditions and shrinks dramatically during prolonged dry periods. As the soil dries out and shrinks, the unsupported concrete may sink and crack.
An improperly prepared soil base can also be the culprit of sinking concrete. Before surfaces such as driveways, patios, and walkways are poured, the supporting soil must be adequately compacted to prevent washout and erosion. This should be done with a mechanical tamping machine for best results.
Once you have any areas of sunken concrete lifted and repaired, it’s important to take the necessary steps to prevent the problem from reoccurring. Have your gutters cleaned twice per year—once in late spring, and again in late fall—and ensure that your home has an adequate number of downspouts to carry water far away from the foundation, walkway, steps, and patio. Contact a drainage specialist to correct any drainage problems in your yard, and make sure that the ground beneath any new concrete surfaces is properly prepared.
What to Expect
Concrete lifting and leveling contractors typically use either a synthetic or mortar-based material to fill any gaps under the concrete surface and support the slab. The foam or liquid is pumped underneath the slab via a hose that connects to small injection holes. As the material fills the void, the sunken areas rise to meet the level of the surrounding concrete. The injection holes are patched and sealed once the process is complete. Foam materials typically cure faster and require smaller injection holes than mortar-based materials.