Mudjacking: Raising Settled Concrete Back to Level

Mudjacking is a concrete leveling method that raises a slab which has settled below its original height. A slurry made with cement is pumped through small holes drilled in the surface, and the existing concrete stays in place. The slurry fills the empty space beneath the slab and lifts it back toward level. It is a less disruptive way to restore a settled surface than tearing it out, which is why homeowners often consider it for driveways, sidewalks, walkways, patios, porch slabs, and garage floors.

Mudjacking serves three goals at once: it restores stability so the slab is properly supported again, it removes the trip hazards that form where two sections of concrete no longer sit flush, and it improves the appearance of a surface that has sunk, cracked, or pitched to one side. The reason a slab settles, though, is almost always in the ground beneath it, and that is where the Carolinas matter. Across the Piedmont, from Charlotte to Greensboro and the Triangle, clay soils take on water through wet seasons and contract through dry stretches. That seasonal swing opens voids under slabs poured on top of the clay, and the concrete drops into the space left behind. In the Sandhills near Fayetteville and Pinehurst, sandy soils drain fast and let fine particles wash out, which quietly loosens the support beneath flatwork. In the Upstate and Midlands of South Carolina around Greenville and Columbia, foothill clay combined with heat and humidity drives a similar moisture load.

Mudjacking suits some of these slabs, but it is not the answer for every one. Whether a slab is a good candidate depends on its condition and on what caused the settlement. HydroHelp911 lifts settled concrete with polyurethane foam injection, and this page explains mudjacking so you can compare the two methods. Every concrete leveling visit begins with a free inspection of the slab and the cause of the settlement.

What to Know About Mudjacking and How the Method Works

HydroHelp911 lifts settled slabs with polyurethane foam, and this page explains mudjacking so you can compare the two. Mudjacking fills the voids under a settled slab with a dense, flowable cement slurry, blended from sand, water, and other fine material, that supports the concrete and pushes it back up.

In mudjacking, a pattern of small holes is drilled through the slab and the slurry is pumped through them under pressure. The lift is done in small, controlled increments so the slab rises evenly. At the target height the holes are patched, and the surface sits flush again, with the trip hazards and the pitched, uneven look corrected. To compare, the polyjacking with expanding foam page shows the method HydroHelp911 uses.

Mudjacking does not change the soil behavior that let the slab settle. Where the soil is already weak or washed out, a lighter polyurethane foam adds less load. In active Piedmont clay, in Sandhills sand where fines keep washing out, or where water drains against the slab, the cause may need correcting first, or piers may be needed.