How each one works
Both methods do the same job. They fill the empty space under a slab and lift it back to grade. The difference is the material, the size of the holes, and how the slab behaves afterward.
Mudjacking
We drill holes about 1.5 to 2 inches across, then pump a slurry of soil, cement, and water under the slab. It's the old-school method and it still works well. The slurry is heavy and cheap.
Foam jacking
Foam jacking, also called polyjacking, uses a polyurethane foam that goes in through holes about 5/8 inch wide. It expands as it sets and lifts the slab. It weighs a fraction of the slurry and cures quickly.
For the full service page, including the process and what affects price, see concrete leveling in Aurora.
What each one costs
Mudjacking typically runs $4 to $8 per sq ft. Foam jacking typically runs $7 to $15 per sq ft. Foam costs more per square foot, sometimes about double. What you get for the extra money is lower weight, smaller holes, and faster use.
Small jobs often hit a minimum charge, because the crew and pump come out either way. One sunken sidewalk section is usually $350 to $650 with mudjacking. Two driveway panels, about 200 sq ft, usually run $1,400 to $3,000 with foam.
Compare both to replacement. Tearing out and pouring new concrete costs more and takes days to cure. If the slab is solid, a lift is usually the cheaper route.
Which one fits which Aurora job
A sunken sidewalk panel
Mudjacking is usually the right call. The slab is light, the lift is small, and cost matters. If the panel is also cracked into pieces, lifting it won't hold, and replacing that panel is better. See our sidewalk and walkway work for that. If the sidewalk is city-owned, check the city's concrete repair policy and Aurora Public Works first.
A driveway that dropped by the garage
Either works. Mudjacking is fine if the ground is firm and the panels are in good shape. Foam makes sense if the soil is soft or the void is deep, since it adds almost no load. If the driveway is also scaling and cracked from end to end, a lift only fixes the elevation. A driveway replacement may be the better dollar.
A garage floor
Foam, usually. It's a big slab with a finished surface, and you want small holes and a quick return to use. The light weight helps over clay.
A patio by the foundation
Foam is the safer choice. Backfill beside a foundation is soft and slow to settle, and you don't want to add heavy slurry load there. The small holes also keep the surface looking clean.
When neither is the right fix
Sometimes we tell people not to lift at all. Here are the cases.
- The slab is badly broken. Many small pieces won't hold a lift. They'll shift again with the next freeze.
- There's an active washout. A void from a leaking line, a downspout dumping at the edge, or runoff will come back. Fill it without fixing the water and you pay twice.
- Drainage is the problem. If the yard pitches toward the slab, lifting doesn't change that. Regrading or a drain comes first.
- The crack is the problem, not the height. A stable, level slab with a crack needs crack repair, not a lift.
In those cases we'll quote a repair or a replacement and explain why.
Why Aurora soil changes the choice
A lot of Aurora sits on expansive clay. It swells in wet springs and shrinks in dry summers, and the movement leaves voids under slabs. Heavy slurry on top of soft clay can compress it and sink again over time. Foam doesn't add that load and doesn't wash out the way soil-based fill can.
On firm, well-drained ground, mudjacking has a long record and the lower price is hard to beat. The soil under the slab, and where the water goes, matters more than the brand name on the method.
After the lift, sealing the joints and cracks helps keep water from getting back under. See concrete sealing for how we do that.
How to decide
Ask three questions. How soft is the ground? How heavy is the slab? How much does a patch on the surface bother you?
- Firm ground, simple slab, cost matters most: mudjacking.
- Soft ground, a heavy or finished slab, or you need it back in use fast: foam.
- Broken slab or active water problem: fix that first, or replace.
We'll look at the slab, probe the void, and give you a written price for the option that fits. If both fit, we'll quote both.
Questions to ask any contractor before a lift
Lifting concrete looks simple from the street, and the quality gap between crews is wide. Before you sign anything, ask a few plain questions.
- How far will each panel lift, and how will you check it as you pump?
- What is under the slab, and did you probe it before quoting?
- What happens to the holes, and will they show on my finish?
- If the water that caused this is still there, what do you recommend?
A contractor who only sells one method will tell you that method fits every job. It doesn't. We run both, so we're free to say which one your slab needs, or that it needs neither.
Frequently asked questions
Is foam jacking better than mudjacking?
Not always. Foam is lighter, cures faster, and leaves smaller holes, but it costs more, typically $7 to $15 per sq ft against $4 to $8 per sq ft. On firm ground, mudjacking is often the smarter spend. On soft clay or decorative slabs, foam is often the better fit.
Why does foam cost more per square foot?
The material is more expensive and the equipment is more specialized. The tradeoff is less weight, smaller holes, and a faster return to use.
How big are the holes?
Mudjacking holes are about 1.5 to 2 inches. Foam holes are about 5/8 inch. Both get patched flush, but the larger holes are easier to see on colored or stamped slabs.
Can I drive on it right after?
Foam is ready for foot traffic in minutes and vehicles shortly after. Mudjacked slabs can take foot traffic the same day, with vehicles after about a day, depending on the mix and weather.
Will the slab settle again?
It can if the cause is still there, like a leak or poor drainage. Fix the water first. Foam resists washout better than slurry, but neither is a cure for bad grading.
When should I replace instead of lift?
When the slab is broken into several pieces, when the surface is badly scaled or cracked everywhere, or when the base is gone. See our driveway replacement page for what that involves.