Choosing a method
Mudjacking vs Foam Leveling
Both of these lift concrete and both of them work. They cost different amounts, last different lengths of time, and suit different slabs. Anyone who tells you one is always the answer is telling you which machine is on their truck.
At a glance
The Differences That Matter
| Mudjacking | Polyurethane foam | |
|---|---|---|
| Cost per sq ft | $3 to $8 | $5 to $25 |
| Service life | 5 to 10 years | 10 to 15 years |
| Hole size | About 1 to 1.5 inches | About the size of a penny |
| Material weight | Heavy, adds load to the soil | Very light, a few pounds per cubic foot |
| Cure time | Sets over hours | Cures in minutes |
| Washout risk | Can erode where water persists | Does not wash out |
| Best on | Stable, well-drained soil | Washed-out voids, weak or wet soil, interior slabs |
Mudjacking
Also called slabjacking, pressure grouting, mud pumping
A slurry of sand, soil and cement is pumped under the slab through larger holes, filling the void and floating the concrete back up.
Where it wins
- Cheaper up front, roughly $3 to $8 per square foot
- Long-established method that plenty of crews around here still run well
Where it does not
- The slurry is heavy, and adding weight to soil that already compacted once is how a slab settles a second time
- Larger holes, more visible patches
- Can wash out over time where water was the original cause
- Longer before the surface takes full load
Polyurethane foam
Also called polyjacking, foam jacking, poly lifting
A two-part polyurethane is injected through holes roughly the size of a penny. It expands underneath, fills the void, and lifts the slab as it goes.
Where it wins
- Cures in minutes, so the surface takes weight the same day
- Very light, around a few pounds per cubic foot, so it adds almost no load to soil that already failed once
- Penny-sized holes rather than the larger ones slurry needs
- Does not wash out, so it is the better choice where water caused the void
Where it does not
- Costs more up front, in the range of $5 to $25 per square foot
- Needs a slab intact enough to lift as one piece
Straight answer
When Mudjacking Is the Right Call
Foam is the better product for most of what settles around here, and it is also the more profitable one to sell, so it is worth saying plainly where the older method is genuinely the better buy.
- The slab sits on stable, well-drained soil and the settling was a one-off rather than ongoing washout.
- It is a large area where the per-square-foot difference adds up to real money and the surface is not visible.
- The slab is nearing the end of its life anyway and you want a few more years rather than a long-term fix.
- Budget is the deciding constraint. A mudjacked slab now beats a foamed slab you keep postponing.
Where water is still moving under the slab, foam is worth the difference, because slurry put into a channel that water is still running through does not stay there.
Common questions
Questions About the Two Methods
- Is foam always better than mudjacking?
- Not always. Foam is lighter, cures faster and resists washout, which matters where water caused the void. Mudjacking costs roughly half as much and is perfectly sound on a stable, well-drained slab where budget is the deciding factor. The method should follow the slab, not the crew's equipment.
- How long does each one last?
- Polyurethane foam typically holds 10 to 15 years, mudjacking 5 to 10 years. Neither is permanent, because neither changes the soil conditions that caused the settling in the first place. What extends both is fixing the drainage that fed the void.
- Why does mudjacking cost less?
- The material is cheap: a slurry of sand, soil and cement mixed on site, against a manufactured two-part polyurethane. The equipment is simpler too. That price gap is real and it is the honest argument for mudjacking on the right slab.
- Does the weight of mudjacking material matter?
- It can. Slurry is heavy, and the soil under a settled slab already failed to carry what was on it. Adding weight to ground that compacted once is how a slab settles a second time. On soil that is stable and simply washed out, it matters much less.
- How big are the holes?
- Foam injection uses holes roughly the size of a penny. Mudjacking needs larger ones, usually an inch to an inch and a half, because slurry will not move through a small port. Both get patched, but the mudjacking patches are more visible afterwards.
- Can I drive on it afterwards?
- With foam, within minutes of the lift, because it cures almost immediately. With mudjacking, the same day in most cases but after the slurry has set rather than straight away. Neither requires the days of cure time that a new pour does.
- Which one should I use on a garage floor?
- Foam is usually the better fit indoors: smaller holes, no curing smell of consequence, immediate load capacity, and no added weight on fill that is already consolidating. The cost difference is also less noticeable on a smaller area than it is across a full driveway.
Neither method fixes the reason the slab moved. That part is on why concrete sinks in Rockford, and the costs are broken down on the pricing page.
Not sure which one your slab needs?
Send a photo and roughly how far it has dropped. You get a recommendation with the reasoning, and a fixed quote.