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Concrete Leveling and Mudjacking in Pittsburgh, PA
A sunken slab usually means the ground under it moved, not that the concrete failed. We fill the void and lift it back to grade. Free on-site estimate.
There is a moment most homeowners recognize. You step onto the patio and one corner gives slightly, or you notice water pooling where it used to run off, or the walkway has developed a lip that catches the toe of your shoe.
The slab did not shrink. Something underneath it went away, and the concrete followed the ground down. That distinction matters, because it decides whether lifting the slab will hold or whether you are about to pay for the same problem twice.
Why Slabs Sink in Western Pennsylvania
Concrete leveling in Pittsburgh is almost always a soil story. Water running off a roof or down a slope carries the fine material out of the compacted stone base, and what it leaves behind is an empty pocket the slab can no longer bridge.
Red bed claystone runs through a lot of Allegheny County, and clay swells when it takes on water and shrinks when it dries. A slab sitting on that gets lifted and dropped a little every season until something cracks or settles for good.
There is a third cause people rarely think about. Large parts of this region sit over worked-out sections of the Pittsburgh Coal Seam, and settlement from old mine workings looks different from a washout. It tends to drop a whole slab evenly rather than tipping one corner.
Signs Your Slab Is a Candidate for Lifting
Not every damaged slab can be lifted, and not every slab that can be lifted needs to be. These are the conditions where concrete leveling is usually the right answer instead of replacement.
- The slab has dropped or tipped, but the concrete itself is still hard and largely intact
- It sounds hollow or rocks slightly when you step near one edge
- Water now stands on a surface that used to drain
- A walkway or patio has developed a lip at a joint that people catch their feet on
- A garage or basement floor has settled away from the wall or the door threshold
- Steps or a porch landing have pulled down and away from the house
What rules a slab out is the concrete itself being finished. If it has broken into loose pieces, or spalling has eaten through a wide area, lifting a failing slab just gives you a level failing slab.
How a Slab Lift Actually Goes
Mudjacking is a small job compared with replacement, but the sequence matters. Skipping the diagnosis is how a slab ends up settling again the following spring.
1. Find out where the void is
We sound the slab to map where it is still supported and where it is spanning air. That tells us how much material the void will take and where the injection ports need to go, and it occasionally tells us the slab should not be lifted at all.
2. Trace the water first
Before anything gets drilled we follow the drainage. A downspout discharging a few feet uphill of a settled corner is the single most common cause we find, and correcting it is what makes the lift permanent instead of temporary.
3. Drill the injection ports
Small holes are cored through the slab in a pattern set by where the void sits. They are kept as few and as small as the job allows, because every port is a patch you will see afterward.
4. Fill the void, then lift
Material goes in under pressure. The void fills first and the slab only begins to rise once it has solid support beneath it, which is why filling and lifting are one continuous operation rather than two separate steps.
5. Patch, clean, and check the fall
Ports are patched, the area is washed down, and we check the finished pitch with a level rather than by eye. A slab that is level but drains toward the house has not been fixed.
Mudjacking or Polyurethane Foam: Which One Belongs Here
Traditional mudjacking pumps a cement and limestone slurry under the slab. It is heavy, it fills large voids economically, and it has held up under Pittsburgh driveways for decades. The trade-off is larger ports and a longer wait before the surface takes weight.
Polyurethane foam injection uses an expanding two-part resin instead. The ports are smaller, the material weighs a fraction of slurry so it does not load a soft subgrade further, and the slab is usually ready for use the same day. It also cures chemically rather than by temperature, which keeps it available later into the season.
Neither is universally better, and any contractor who offers only one will recommend it for everything. Large voids under a heavy driveway generally favor slurry. Precise lifts, interior floors, and slabs over soft or saturated ground generally favor foam. We will tell you which one your slab calls for and why.
Concrete Leveling Across the Pittsburgh Area
We handle concrete leveling and mudjacking throughout the city and the surrounding boroughs, including Squirrel Hill, Brookline, Mount Washington, Mt. Lebanon, Bethel Park, Upper St. Clair, Dormont, Ross Township, McCandless, Wexford, Shaler, Monroeville, Penn Hills, Plum, Robinson Township, Moon Township and Coraopolis.
Newer subdivisions around Cranberry Township, Marshall Township and Franklin Park see settlement early, usually at a garage apron or a patio edge where the fill was compacted least. Through the Mon Valley, in McKeesport, West Mifflin, Munhall, Duquesne and Clairton, we read settlement patterns more carefully before recommending a lift.
Concrete Leveling FAQs
How long does concrete leveling take?
Most residential slabs are lifted in a single visit, often in a few hours. Polyurethane foam is typically ready for foot traffic almost immediately and vehicles the same day. Slurry mudjacking needs longer to set before the surface takes weight.
Will I be able to see where the holes were?
Yes, though they are small and get patched with a color-matched mix. On an older weathered slab the patches stay visible up close. If appearance matters more to you than cost, that is worth raising before we start.
Is a lifted slab permanent, or will it sink again?
The lift itself is permanent. Whether it stays level depends on whether the cause was corrected. Fill a void without fixing the downspout that created it and the water will simply do the same thing again.
Can you lift a slab that is already cracked?
Often, yes. A slab cracked into two or three sound pieces can usually be lifted and the cracks sealed afterward. A slab broken into many loose fragments cannot, because there is nothing solid left to lift against.
Does concrete leveling work on garage and basement floors?
It does, and interior floors are one of the better applications, because replacement there means demolition inside the building. Foam is usually the material of choice indoors for the smaller ports and the faster return to use.
Can this be done in winter?
Polyurethane foam injection cures chemically rather than by air temperature, so it runs later into the season than most concrete work. Slurry mudjacking is limited by freezing ground and freezing material, so it generally stops earlier.
Get Your Sunken Slab Looked At
Send a photo and tell us roughly when the settling started. We will come out, find where the void is, trace what caused it, and give you a written scope before any work gets scheduled.