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Concrete Finish Notes · Mudjacking vs Polyurethane foam jacking
Mudjacking or foam leveling: lifting a sunken slab before finishing it
Mudjacking pumps a cement slurry under a sunken slab through larger holes; it costs less per square foot but adds weight and leaves bigger patches. Polyurethane foam lifts through small holes, cures in minutes and adds little weight, but costs more. For interior slabs you plan to polish, foam's small holes blend better; for exterior slabs on stable soil, mudjacking is often enough.
A slab that has sunk or tilted has to be addressed before polishing, staining or sealing, because grinding follows the existing surface. Lifting the slab back into place is often cheaper than replacing it, and two methods dominate: mudjacking with a cementitious slurry and injecting expanding polyurethane foam. Both work by filling voids beneath the slab and pushing it up.
This page compares how each performs in real situations, what each costs over time, how soil and climate affect the result, what the repair looks like on a finished floor, and how to compare bids. Pricing comes from HomeGuide's leveling guide. It is written for owners who plan to finish the slab afterward, where the look of the repair matters as much as the lift.
Both lift a settled slab by pumping material beneath it. Mudjacking uses a cement slurry through larger holes at lower cost; foam jacking uses expanding polyurethane through small holes at higher cost with less weight and faster cure. Neither fixes the cause of settlement.
| Factor | Mudjacking | Polyurethane foam jacking |
|---|---|---|
| Upfront cost | $4–$9 per sq ft (HomeGuide 2025) | $8–$25 per sq ft (HomeGuide 2025) |
| Hole size | About 1–2 inch holes, patched | About 5/8 inch holes, nearly invisible |
| Weight added | Heavy slurry; can resettle soft soils | Light foam; less load on weak fill |
| Cure and use | Hours to a day | Minutes; immediate use |
| Longevity | Years; slurry can wash out | Long; foam is water-resistant |
| Fit for polishing | Larger patched holes show after polishing | Small holes are easier to blend |
| Best for | Garages, driveways, patios on stable soil, budgets | Interior slabs to be finished, soft soils, voids |
Verdict
Foam wins for an interior slab that will be polished or stained afterward: the holes are small, the cure is immediate and the added weight is negligible on weak fill. It costs more per square foot in HomeGuide's $3–$12 per sq ft range, and the premium is often worth it inside a house. The leveling page explains when lifting is the right method at all.
Mudjacking wins on exterior slabs and budgets, where the larger patched holes do not matter and the slurry's weight is acceptable on stable soil. It loses on soft or wet soils that can resettle under the added load, and on slabs that will receive a fine finish. Both lose if the cause of settlement, usually water, is not addressed.
Which sunken slabs suit mudjacking, and which suit foam?
Mudjacking suits driveways, sidewalks, patios and garage slabs on reasonably stable, well-compacted soil where a modest lift is needed and cost matters. Attached garages are common: our analysis of the federal government's 2024 household survey found 42.9% of homes have an attached garage, and 53.0% of owner-occupied attached-garage homes sit on a slab foundation. The slurry is dense and supports the slab well once cured. The larger holes are less of a concern on exterior concrete, particularly if it will be sealed rather than polished. It remains the most common method for exterior flatwork. Stable soil is the condition that makes it last.
Foam suits interior slabs, which matter most in slab-on-grade homes, 32.4% of occupied homes by the same analysis, as well as slabs over weak or wet soils, and slabs that will be polished or stained where small, neat holes matter. It is lighter, so it adds less load to soft fill that may have caused the settlement in the first place. It also cures quickly, so the slab can be used almost immediately. The grinding and leveling service covers both methods. Its higher price is often justified indoors, where appearance and speed matter most.
What does each lifting method cost over ten years?
HomeGuide's leveling guide lists mudjacking at $4 to $9 per square foot and polyurethane foam at $8 to $25, with overall concrete leveling at $3–$12 per sq ft and minimum job fees of $300 to $700. On a single garage panel or short walk, the minimum fee may dominate. On larger areas, foam's higher per-foot price becomes significant. For a single panel, compare total prices rather than per-foot rates.
Over time, durability tips the balance. Mudjacking slurry can wash out or compress if water moves under the slab, and heavier material can cause further settling on weak soils, leading to repeat lifts. Foam resists water and adds little weight, so repeat work is less common. If the soil is stable and drainage is good, mudjacking's lower price often holds up well.
How do soil, water and climate affect the lift?
Settlement usually has a cause: poorly compacted fill, erosion from downspouts or leaks, or expansive clay that shrinks in drought. Lifting without fixing the cause invites the slab to sink again. Redirect downspouts, fix leaks and regrade soil away from slabs before or alongside the lift. A contractor who asks about downspouts and leaks before quoting is diagnosing, not just selling a lift. HomeGuide's leveling range of $3–$12 per sq ft includes mudjacking at $4 to $9, and regrading is the preventative half of any lift.
In freeze-thaw climates, water under a slab can heave it in winter and let it drop in spring, so drainage is critical. In areas with expansive clay, foam's light weight and water resistance are advantages. Neither method stabilizes deep soil problems; if settlement is severe or ongoing, a geotechnical or structural opinion may be needed before any lifting. Fixing gutters and grading first is usually the cheapest part of the whole repair.
What does the repair look like on a polished or stained floor?
Holes are the visible legacy. Mudjacking typically uses larger holes, and foam uses much smaller ones, as the comparison table shows. After lifting, holes are patched with a cementitious or epoxy filler. On a polished floor, those patches show as spots of different color and texture. Smaller holes are easier to blend, and a dye can reduce contrast. Ask where the holes will go; placing them along joints or in low-traffic areas makes them less noticeable.
Lifting also changes joint and crack widths slightly, and cracks that existed before may remain visible. Plan the lift before the finish, allow patches to cure, and include the patched areas in your mock-up so you can see how they will look. The grind-and-seal versus polish comparison may help if the patches push you toward a sealed rather than polished finish. Resealing joints after the lift keeps water out of the voids that were just filled.
What mistakes cause lifted slabs to fail?
The most common mistake is lifting without fixing the water or soil problem that caused settlement. Another is over-lifting, which can crack the slab or open voids elsewhere. Operators should lift gradually while monitoring the slab with a level or laser. Injecting too much material into large voids can also push material into places it should not go, such as under adjacent slabs or into drains. Ask how the operator will monitor the lift.
For interiors, a mistake is lifting without checking for plumbing under the slab. Drilling can hit pipes, and foam or slurry can enter damaged lines. A contractor should ask about utilities and may locate them first. On slabs that will be polished, another mistake is scheduling the polish too soon after lifting, before patches have cured and the slab has settled into its new position.
When is lifting the wrong answer for a sunken slab?
Lifting restores support under a slab that is otherwise sound. It is the wrong answer when the slab is broken into many small pieces, when settlement comes from an ongoing leak or soil movement that has not been fixed, or when the floor must be removed anyway for plumbing or drainage work. In those cases, lifting spends money on concrete that will be replaced or will sink again. The opposite error is waiting: HomeGuide puts a leveling project at $700 to $5,000, and erosion under a slab rarely stops on its own, so the bill tends to grow.
For interior floors with modest dips rather than true settlement, an overlay or patching may be the better fix. HomeGuide lists self-leveling overlays at $2 to $5 per square foot, within its broader leveling range of $3–$12 per sq ft. If the floor is headed for a polish, read how an overlay will look beside original concrete on the polishing service page before choosing.
Replacement is the remaining option. It costs more and takes longer because of demolition, disposal and curing, and it may need permits, but it gives a clean, level slab. For a floor you plan to polish, new concrete placed with polishing in mind can produce a more even finish than a heavily repaired old slab; Angi prices a new slab for polishing at $4–$8/square foot.
- Slab broken into many small pieces
- Active leak or erosion not yet fixed
- Plumbing or drain work planned under the slab
- Dips from uneven placement rather than settlement
How should you compare bids for slab lifting?
Ask each contractor to identify the likely cause of settlement, the method and material, the number and size of holes, the expected lift, and how they will monitor it. Confirm whether drainage fixes are included or excluded, how holes will be patched, and whether joints will be sealed afterward. Ask for any warranty terms in writing and what they cover. A bid that skips the cause is pricing only half the job.
Compare the total project price, not just the per-square-foot figure, since minimum fees and mobilization often dominate small jobs. If you will polish afterward, share that plan so the contractor can choose hole locations and patch materials accordingly. The leveling cost page and estimate request help you gather comparable prices. Written scopes make it far easier to see which bid includes drainage fixes and patching.
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Mudjacking or Polyurethane foam jacking: what homeowners chose
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Mudjacking vs Polyurethane foam jacking: questions
Will lifting a slab fix the crack across it?
It closes the step at the crack so the two sides are level, but the crack remains and must be filled. If the slab settled because water washed out the fill, the crack may continue to move until drainage is corrected. A pro should look at downspouts and grading before lifting anything.
Can a slab be lifted too much?
Yes. Over-lifting cracks the slab or creates a new high spot at the far edge. Pros lift in stages while monitoring with a level, and foam's fast expansion needs a careful hand. Ask how the pro controls lift and what happens if a section rises unevenly. Grinding can then take down a small remaining lip.
How much can a sunken slab be lifted?
Many slabs can be raised several inches, but the practical limit depends on how the slab is connected to adjacent concrete, its condition and the size of the voids. Slabs that are badly cracked or broken into small pieces may not lift evenly. A contractor should explain what lift is realistic before starting.
Does lifting work on a basement floor?
Sometimes. Basement slabs sink less often than exterior ones, and interior lifting needs care around plumbing, drains and walls. Foam is usually preferred indoors for its smaller holes and light weight. If a basement floor has settled significantly, a structural assessment is sensible before lifting.
Is replacing the slab ever better than lifting it?
Yes, when the slab is badly broken, has settled repeatedly, or when you are changing plumbing or drainage beneath it anyway. Replacement costs more and involves demolition, curing time and possibly permits, but it resets the slab entirely. For a floor you plan to polish, new concrete also gives a clean start.
Can I polish the slab immediately after foam leveling?
Foam cures quickly, but hole patches need time to cure before grinding, and the slab benefits from a short period to confirm it has stabilized. Coordinate the two contractors and ask how long the patch material needs. Rushing risks patches that grind unevenly or crack.
Will lifting stop a crack from growing?
Lifting can reduce stress on a slab by restoring support, which may slow further cracking, but it does not close or repair existing cracks. Those are filled separately. If cracks keep widening after lifting, the underlying soil or water issue has not been fixed.
Other comparisons
ComparisonPolished concrete vs Epoxy coatingChoose polished concrete when the slab is sound, reasonably clean and you are happy to see its character; it lasts decades and needs little upkeep.
ComparisonAcid stain vs Concrete dyeAcid stain reacts chemically with the slab to create permanent, mottled earth tones and usually needs a sealer.
ComparisonHoned / satin (CPC Level 2) vs High gloss (CPC Level 4)Honed or satin finishes (CPC Level 2) cost less, hide dust and scuffs, and generally perform better underfoot when wet, which suits most homes.
ComparisonGrind and seal vs Full polishGrind and seal smooths the slab with a few passes and relies on a sealer for sheen and protection, so it costs less up front but needs recoating.
Service guides
Service guideConcrete PolishingConcrete polishing grinds an existing slab with progressively finer diamond abrasives, hardens it with a densifier and refines it to a specified sheen and aggregate exposure.
Service guideConcrete Staining & DyeingStaining and dyeing add color to a concrete slab by penetrating the surface rather than covering it, so the aggregate, patches and variation remain part of the look.
Service guideConcrete Grinding & LevelingGrinding uses coarse diamond tooling to remove coatings, adhesives, lips and high spots and to open a surface profile for whatever finish follows.
Service guideConcrete Sealing & ProtectionSealing and protection treatments defend a concrete floor against stains, moisture and wear, and they range from penetrating silicates and siloxanes that leave the look unchanged to film-forming acrylics, urethanes and epoxies that add gloss and a wear layer.
Free planning tools
Free toolPolished concrete cost calculator: a planning range for your square footageSize, material tier and complexity in, a realistic budget range out.
Free toolConcrete finish quiz: can you read a polishing proposal?9 questions that show what you already know and what to check next.
Free toolPolls: what other homeowners planning concrete floors decidedSee what other planners chose and add your vote.
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