Look at your driveway where it meets the garage. Is there a step down? Does your sidewalk tilt toward the house? Has one corner of the patio dropped a few inches? Concrete settles when the soil under it moves — and replacing the whole slab is expensive, messy, and slow. Concrete lifting raises the existing slab back to level by filling the voids underneath. It costs far less than replacement and it is usually done in a day.
Why concrete settles
Concrete is heavy and the ground is not always cooperative. The usual causes of settlement are soil that was never compacted properly before the slab was poured, clay soil shrinking during dry spells and leaving voids, water washing soil out from under the slab, and tree roots or buried organic material decomposing underneath. In Charles County, the shrink-swell cycle of our clay soil is behind a lot of it — the ground drops away in dry summers and the slab follows it down.
Settlement is not just ugly. A driveway slab that has dropped at the garage creates a trip hazard and lets water pool against the house. A sidewalk tilted toward the foundation sends rainwater straight to your basement walls. A sunken patio holds water where you want to sit. And uneven concrete around a pool is a safety problem. Lifting fixes the function, not just the look.
Mudjacking vs polyurethane foam
There are two ways to lift concrete. They share the same idea — pump material under the slab to fill voids and raise it — but the materials are very different.
Mudjacking
Mudjacking, the older method, pumps a cement-based slurry under the slab through large drilled holes. It works and it is usually the cheaper option. The downsides: the slurry is heavy, so it adds weight to soil that already failed once. It needs large holes, takes longer to cure, and can wash out over time if water gets under the slab again.
Polyurethane foam lifting
Foam lifting injects a two-part polyurethane foam that expands as it cures, filling voids completely and lifting the slab with precise control. The foam is extremely light — it adds almost no weight to the soil. It cures in minutes, so the concrete can be used almost immediately. The holes are small, about the size of a penny, and easy to patch. The foam is waterproof, so it does not wash out, and it actually stabilizes the soil underneath by filling every void.
For most residential work — driveways, sidewalks, patios, pool decks — foam is the better choice. It is more precise, cleaner, faster, and longer-lasting. Mudjacking still has a place for very large commercial slabs where material cost dominates, but for a homeowner, foam wins on nearly every measure that matters.
What can be lifted
Most exterior flatwork is a candidate: driveways, sidewalks, walkways, patios, pool decks, garage floors, and stoops. The slab needs to be structurally sound — lifting fixes settlement, not a slab that is crumbling apart. A slab that is cracked into many small pieces or has deteriorated beyond repair is a replacement job, and an honest contractor will tell you so. But a solid slab that has simply settled? That is exactly what lifting is for.
What lifting day looks like
The crew drills small holes through the slab in a grid pattern, injects the foam under each section, and watches the slab rise in real time. The lift is controlled to a fraction of an inch — sections can be raised evenly so the surface ends up level, not just higher. The holes are patched with a color-matched material. Most residential jobs take a few hours. You can drive on the concrete the same day. Compare that to replacement: days of demolition, forming, pouring, and a week or more of cure time before you can use it.
Because the foam fills every void underneath, the slab ends up better supported than it was when it was new. That is why foam lifting lasts: it fixes the support problem, not just the height problem.
How long foam lifting lasts
Polyurethane foam does not break down underground. It is waterproof, it does not compress under the slab, and it bonds to the soil and the concrete. Once the voids are filled and the slab is supported, there is nothing left to settle — unless new voids form from a new water problem. That is why the warranty question matters: ask what the warranty covers and for how long, and get it in writing.
The main threat to a lifted slab is water returning underneath. A broken sprinkler line, a downspout dumping next to the driveway, or grading that sends water under the patio can wash out soil and create new voids over the years. Keep water managed and a foam lift should last as long as the slab itself. Mudjacking, by contrast, can erode if water gets under the slab again, since the slurry is not waterproof — one more reason foam is the better long-term choice.
Lifting vs replacement: the honest math
Lifting typically costs far less than tearing out and replacing concrete — often a fraction of the replacement price, since there is no demolition, no hauling, no new concrete, and no week of cure time. It is also faster and far less disruptive to your landscaping. Replacement makes sense when the slab itself is failing — badly cracked, spalling, or deteriorated. Lifting makes sense when the slab is sound but the ground under it moved. If someone tries to sell you replacement for a solid settled slab, get a second opinion.
For a broader sense of how repair costs compare across foundation work, see our guide to foundation repair costs in Maryland.
Preventing future settlement
Lifting fixes today's settlement, but keeping it fixed means managing water. Make sure downspouts discharge away from the lifted areas, grading slopes away from slabs, and no new water sources develop underneath — like a leaking hose bib or irrigation line. Our foundation maintenance tips cover the habits that keep soil stable around your home. And if the settled concrete is part of a bigger foundation problem — a slab foundation home that is settling, for example — read how foundation repair works to understand when lifting is enough and when piers are needed.
Free concrete lifting estimate
Send us a description of your settled concrete — or better yet, let us come look at it. Our free inspection includes measurements of the settlement, an honest answer about whether lifting or replacement is right, and a written quote. Fill out the form below to schedule it.