Mudjacking in St. Louis, MO: Costs, Process and When It Works
If a section of your driveway, sidewalk, patio, or garage floor has sunk in St. Louis, mudjacking is one of the most common and affordable fixes homeowners around the metro turn to before considering a full slab replacement. Mudjacking, also called slabjacking, works by pumping a slurry of soil, cement, sand, and water through small drilled holes to lift a sunken concrete slab back to level. It's a technique that's been used in the St. Louis area for decades on the loess and glacial till soils that underlie much of the region, where poor original compaction, erosion around older utility trenches, and freeze-thaw cycling all contribute to slabs settling unevenly over time. This guide covers what mudjacking actually costs in the St. Louis market, how it compares to polyurethane foam injection, and when a sunken slab is a sign of a bigger foundation issue rather than a simple concrete leveling job.
By Jason Green · Foundation Repair · Published August 28, 2026 · 8 min read
Why concrete sinks in St. Louis
Most sunken slabs in the St. Louis metro trace back to soil that wasn't compacted well when the concrete was originally poured, especially over backfilled utility trenches or old basement excavation edges. The loess and glacial till soils common here compress unevenly under a slab's weight over years, and heavy spring rains wash fine soil particles out from underneath a slab through small gaps and utility sleeves, creating voids that the concrete eventually settles into.
Freeze-thaw cycling through St. Louis winters makes existing settlement worse, since water trapped under a slightly sunken slab edge freezes and expands, then thaws and drains away, gradually enlarging the void beneath the concrete. This is why sunken slabs in the region often get visibly worse each winter rather than staying stable once they first appear.
How mudjacking works
A mudjacking crew drills a pattern of one-to-two-inch holes through the sunken slab, then pumps a limestone-based or soil-cement slurry underneath through those holes under pressure, gradually lifting the slab as the material fills the void and pushes upward. Once the slab reaches the target level, the holes are patched with a matching concrete or mortar mix.
The whole process for a typical driveway apron or patio section usually takes a few hours to half a day, and the slab can generally handle light foot traffic within a day, though vehicle traffic on driveways is usually held off for a day or two to let the patched holes cure.
Mudjacking versus polyurethane foam in St. Louis
Mudjacking costs less per square foot than polyurethane foam injection and has a long local track record, which is part of why it remains popular for driveways, sidewalks, and patios throughout the metro. The tradeoff is that the slurry mix is heavier than foam, so on a spot where the underlying soil is still eroding or settling, a mudjacked slab has a somewhat higher chance of needing a touch-up sooner than a foam-lifted one.
Polyurethane foam cures faster, uses smaller holes, and adds far less weight to already-weak soil, which matters on sections near a downspout or drainage path where erosion is ongoing. Many St. Louis contractors offer both and will recommend one over the other depending on the size of the slab, how much lift is needed, and whether the underlying erosion problem has been fixed first.
What it costs in the St. Louis metro
Pricing depends on the size of the slab, how much lift is needed, and accessibility for the pump equipment. A typical residential driveway section runs less than a full slab replacement would cost, which is the main appeal of mudjacking for homeowners trying to avoid tearing out and repouring concrete.
Sidewalks and smaller patio sections tend to be priced with a minimum project fee even if the square footage is small, since mobilizing the pump truck and crew has a baseline cost regardless of job size.
When mudjacking isn't the right fix
If a slab has cracked into several separate pieces that are moving independently, mudjacking can lift the pieces unevenly and make the cracking more visible rather than solving it. Similarly, if the void underneath is caused by an active drainage problem, like a downspout still dumping water against the foundation or a broken drain line washing soil away, mudjacking without first fixing that underlying cause is likely to need a repeat lift within a few years.
If the sunken slab is a covered porch or patio that's structurally tied into your home's foundation rather than a freestanding driveway or walkway, it's worth having a contractor confirm the settlement isn't connected to a foundation issue before treating it as a simple mudjacking job. For structural basement wall or foundation concerns, see our St. Louis foundation repair cost guide.
Typical cost ranges
| Mudjacking, small patio or walkway section | $350 - $900 |
| Mudjacking, per square foot | $3 - $6 |
| Driveway apron or full driveway section | $800 - $2,500 |
| Garage floor slab | $600 - $1,800 |
| Polyurethane foam alternative, per square foot | $5 - $8 |
| Full slab replacement (if lifting isn't viable) | $7 - $13 per square foot |
Ranges are general estimates gathered from homeowner-reported quotes, not an offer or a quote for your project.
Common questions
How much does mudjacking cost in St. Louis?
Most residential mudjacking jobs, like a driveway apron or patio section, run $350 to $2,500 depending on size, with pricing often figured around $3 to $6 per square foot plus a project minimum.
How long does mudjacking last in St. Louis?
A well-done mudjacking lift commonly holds for 5 to 10 years, though slabs over an area with ongoing soil erosion or drainage problems may need a touch-up sooner.
Is mudjacking better than replacing the slab?
For a slab that's structurally sound but has settled unevenly, mudjacking is usually cheaper and faster than replacement. If the concrete is badly cracked or broken into multiple shifting pieces, replacement is often the better long-term fix.
Does mudjacking fix the cause of settling?
No. Mudjacking lifts the slab back to level but doesn't address soil erosion, poor drainage, or a broken pipe underneath. If the same area sinks again quickly, the underlying cause needs to be diagnosed and fixed.
Can mudjacking be used on a garage floor?
Yes, mudjacking is commonly used on garage floor slabs that have settled, as long as the slab itself isn't badly cracked. A contractor can check whether the slab is a good candidate before drilling.
Do I need a permit for mudjacking in St. Louis?
Mudjacking on a freestanding driveway, patio, or walkway that isn't part of the home's structural foundation typically doesn't require a permit in the City of St. Louis or St. Louis County, but it's worth confirming with your contractor or local building department if the slab is attached to the house.
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