Mudjacking vs foam concrete leveling
When a driveway, walk or patio slab settles, you rarely need to tear it out — you can lift it back into place. Two methods dominate: traditional mudjacking and polyurethane foam. This guide compares how they work, what they cost, and when either beats a full replacement.
Two ways to lift a slab
Both methods drill small holes in a settled slab and inject material underneath to raise it. The difference is what gets pumped in:
- Mudjacking (slabjacking): a cement-and-soil slurry ("mud") is pumped under the slab to fill voids and float it up. Proven, widely available, and cheaper per square foot; the slurry is heavy and the access holes are larger.
- Polyurethane foam (foam jacking): a two-part foam is injected that expands, fills voids and lifts the slab. Lightweight (it will not add load to weak soil), uses smaller holes, cures in minutes, and resists washout — but costs more per square foot.
The cost formulas
Both are priced by the area lifted (sometimes by the number of injection holes), from the rate you enter:
Mudjacking = area × price per sq ft (or holes × $/hole)
Foam = area × price per sq ft
Price mudjacking in mudjacking / slabjacking cost, and set foam against mud in concrete leveling cost and foam vs mud jacking compare.
A worked comparison
Lifting a 200 sq ft slab: mudjacking at $5 per square foot = 200 × $5 = $1,000; foam at $8 per square foot = 200 × $8 = $1,600. Foam costs about $600 more here — the delta you weigh against its advantages (lighter weight, smaller holes, faster cure, washout resistance). Both are dramatically cheaper than tearing out and repouring 200 sq ft of concrete, which starts well above either figure once you add demolition and haul-off.
Which to choose
| Factor | Mudjacking | Foam |
|---|---|---|
| Cost per sq ft | Lower | Higher |
| Weight added to soil | Heavy slurry | Very light |
| Hole size | Larger | Smaller |
| Cure / return to use | Slower (a day) | Minutes |
| Washout resistance | Lower | Higher |
Rule of thumb: choose mudjacking when budget leads and the soil is stable; choose foam for weak or wet soils, when you need the slab back in service quickly, or when the smaller holes matter cosmetically.
When lifting is not the answer
Leveling raises a slab that has sunk; it does not fix a slab that is crumbling, badly cracked or spalling. If the concrete itself has failed, replacement (or resurfacing for a surface problem) is the right call — see crack repair and resurfacing. And note that lifting a slab does not fix the reason it sank; if a drainage or erosion problem caused the void, address that too, or it can settle again.
What lifting a slab actually involves
The process is quick and far less disruptive than replacement, which is a big part of the appeal. A crew drills a pattern of small holes through the settled slab, pumps slurry or expanding foam through them to fill the void underneath and raise the concrete back to grade, checks the level as they go, then patches the holes. On a modest slab it is often a few hours, and with foam the concrete is usually back in service the same day. There is no demolition, no haul-off, no new forms and no cure time to wait out, which is why lifting costs a fraction of tear-out even before you count the mess and downtime you avoid. The visible aftermath is a grid of patched holes — smaller and less obvious with foam, larger with mudjacking.
Which slabs can be lifted — and which cannot
Leveling is the right tool for a slab that has sunk as a unit but is otherwise intact: a settled driveway section, a sidewalk panel that has dropped at a joint, a garage floor or patio that has developed a slope. It is the wrong tool when the concrete itself has failed — a slab that is badly cracked into many pieces, crumbling, spalling or curling has lost the integrity that lifting relies on, and replacement is the honest answer. It also will not cure the cause: if expansive soil, a plumbing leak, poor drainage or erosion created the void, that has to be addressed or the slab can settle again. A good contractor will tell you when a slab is not a candidate; be wary of one who wants to jack a slab that is plainly breaking apart.
The bottom line
Both mudjacking and foam lift a settled slab for a fraction of replacement cost: mudjacking is cheaper per square foot, foam is lighter, faster and more washout-resistant. On a 200 sq ft slab that is about $1,000 vs $1,600. Compare your own numbers in concrete leveling cost. These are planning estimates — get itemized quotes from licensed, insured contractors.