Mudjacking vs Polyjacking

1. How Do Mudjacking and Polyjacking Compare?

Mudjacking and polyjacking solve the same problem. A concrete slab has sunk because the soil under it compacted, washed out or shifted, leaving a void. Both methods drill holes through the slab, pump material into the void under pressure, and use that pressure to lift the slab back toward level. Once the slab is up, the holes are patched and the material stays in place as the new support. The difference is the material, and almost every practical trade-off follows from it.

The figures in the table are typical ranges, not specifications. Mix designs for mudjacking slurry vary from contractor to contractor, and lifting foams come in several densities for different jobs. Prices vary by region and change over time. But the direction of each comparison is consistent: slurry is heavier, cheaper and slower; foam is lighter, more expensive per square foot and faster.

One point the table does not capture is skill. Either method done well beats the other done badly. A careful mudjacking crew that fixes the drainage problem will deliver a better result than a foam crew that over-lifts and cracks the slab. When you compare quotes, compare the companies as well as the methods.

If you are mostly trying to work out a budget, our concrete leveling cost guide breaks down typical totals by job size, from a single sidewalk square to a whole driveway, and lists the extras that often get left off quotes.

2. How Does Each Method Actually Lift the Slab?

Mudjacking, also called slabjacking or pressure grouting, is the older method. The contractor drills a pattern of holes through the slab, then pumps a slurry under it with a hydraulic pump. The slurry fills the void first, then, as pressure builds, starts pushing the slab up. The crew moves from hole to hole to raise the slab evenly, watching for the point where it meets its neighbors. Once the slab is at height, the holes are filled with a cement patch.

Polyjacking uses a two-part polyurethane that is mixed at the injection gun and expands as it reacts. The contractor drills small holes, installs injection ports, and shoots the liquid under the slab. The foam expands to fill the void, then expands further and lifts the slab. Because the reaction is fast, the crew injects in small doses and watches the slab closely. Once the slab is at height, the ports come out and the holes are patched.

Both methods depend on judgment. Lift too fast and the slab can crack or rise unevenly. Lift one side too far and you create a new trip hazard in the other direction. Experienced crews often use a straightedge or laser to track the slab as it moves, and they lift slowly near the target height. This is why a confident estimate of how a job will go, before any holes are drilled, is worth less than a crew's track record.

Neither method fixes the reason the void formed. Water from a downspout, a leaking line or poor grading carries soil away. Expansive clay soils shrink and swell with moisture. Fill that was not compacted properly when the house was built settles over the years. Animals burrow under patios. Lifting the slab restores its height, but if the cause is still active, the void will start forming again, under slurry or foam.

That is why the first question a good contractor asks is what caused the settling. If they do not ask, ask them yourself, and make fixing the cause part of the job, whether that is extending a downspout, sealing joints or regrading soil away from the slab.

3. Do Hole Size and Material Weight Really Matter?

Hole size matters most on concrete people look at. Mudjacking holes, commonly around 1.5 to 2 inches across, are patched with cement and remain visible as a series of round dots, especially on colored, stamped or exposed aggregate concrete. Foam holes, commonly around 5/8 of an inch, are much less noticeable. On a plain gray driveway or a garage apron, many owners stop noticing either after a season. On a stamped patio, the difference is real.

Fewer and smaller holes also mean less drilling stress on the slab. A slab that is already cracked or thin can be weakened a little more by each large hole. That does not make mudjacking unsafe on cracked concrete, but it is one reason foam is often preferred for older or more fragile slabs.

Weight is the bigger technical difference. Cement slurry is heavy, typically weighing on the order of 100 pounds or more per cubic foot. Lifting foams commonly weigh just a few pounds per cubic foot. If the void is deep and the soil below is soft, pumping in a large volume of heavy slurry adds significant load to soil that has already proven it cannot hold the slab. That extra load can contribute to the slab settling again.

Foam adds very little weight, which makes it the better match for soft, wet or poorly compacted soils, and for deep voids where a lot of material is needed. Some contractors also use foam to stabilize soils beneath a slab, injecting deeper to fill voids before lifting. Mudjacking remains a sound choice where the soil is firm and the void is modest, because the slurry provides solid support on a stable base.

4. How Soon Can You Drive on It?

This is the difference homeowners feel most. Polyurethane lifting foam reacts and reaches working strength quickly. Many contractors let you walk on the slab almost immediately and drive on it within roughly 15 to 30 minutes after the last injection. For a driveway that is your only way in and out, that means the job is done in an afternoon without moving the cars to the street overnight.

Mudjacking slurry needs time to set before it can carry a vehicle. Contractors commonly ask you to stay off the slab with vehicles for at least 24 hours, and longer in cool or damp weather when cement-based materials set more slowly. Foot traffic is often fine sooner, but follow the crew's specific instructions, because driving on soft slurry can push the slab back down or crack it.

Weather also affects scheduling. Cement-based materials are sensitive to cold, and most contractors avoid mudjacking when freezing temperatures are expected. Foam can typically be installed across a wider range of temperatures, though manufacturers set limits for both the material and the slab surface. In cold climates, foam crews sometimes work later into the season than mudjacking crews.

For a back patio or a side walkway, cure time rarely matters. You can avoid a patio for a day without inconvenience. For a commercial entrance, a busy driveway or a garage floor that has to hold a car tonight, foam's speed is a genuine advantage that can justify the price on its own.

5. Which One Lasts Longer?

Foam generally has the edge, with one important condition. Polyurethane lifting foam is closed-cell and does not absorb water, and it does not wash away the way soil-based slurry can if water keeps flowing under the slab. Mudjacking slurry is durable when it stays dry and supported, but where water keeps running beneath the slab, it can erode over time and leave a new void.

The condition is that both methods depend on the cause of settling being fixed. A foam-lifted slab beside a downspout that pours water at its edge can still settle, because the soil beneath the foam keeps washing out. A mudjacked slab with good drainage, sealed joints and stable soil can last many years. The drainage fix is worth more than the choice of material.

Typical expectations are a few years to a decade or more for mudjacking with drainage corrected, and often longer for foam. You will see much bigger claims in marketing on both sides. Be skeptical of any lifetime promise and read the warranty terms instead: what is covered, for how long, and what conditions void it.

One more longevity factor is weight on soft soil, covered above. Heavy slurry over weak soil can contribute to the slab sinking again. That is not a flaw in mudjacking so much as a reason to choose foam in that specific situation. On firm soil, the weight difference has little effect on how long the repair lasts.

After either lift, seal the joints between slabs and fill any cracks to keep water out. A flexible joint sealant over backer rod handles the joints, and our picks for the best concrete crack filler cover cracks from hairline to wide, moving to static. That small job is the cheapest insurance you can buy for a leveling repair.

6. Is Polyjacking Worth the Extra Cost?

Mudjacking typically costs around $3 to $6 per square foot, while polyjacking commonly runs around $5 to $25 per square foot. Foam is wider because it is often priced by the pound of material injected, and void size varies enormously. For many small jobs, both methods land near the contractor's minimum charge, so the real difference may be smaller than the per-square-foot numbers suggest.

Over the life of the repair, the gap can shrink further. If foam lasts meaningfully longer on your soil, and you avoid paying for a second lift, the higher upfront price can be the cheaper choice over a decade. If your soil is firm and the drainage is fixed, mudjacking may last long enough that foam's premium buys little.

There are also costs neither quote shows. Mudjacking's larger holes may need color-matched patching on decorative concrete, which some contractors charge for. A day without the driveway may mean parking on the street or rearranging plans. Foam's speed and smaller holes reduce both. Weigh those against the headline price.

Compare either method against replacement. Leveling, by either method, commonly costs a fraction of tearing out and repouring a slab, which is often $8 to $18 per square foot including demolition. If the concrete is sound, leveling is usually the better buy. If it is broken up, crumbling or near the end of its life, put the money toward a new slab instead. Our concrete driveway cost guide covers replacement pricing in detail.

7. So Which Should You Pick?

Choose polyjacking when you need the slab back in service quickly, when the soil under it is soft, wet or washed out, when the void is deep, or when the concrete is decorative and you want small, discreet holes. It is also a reasonable choice for older or thinner slabs where fewer, smaller holes reduce drilling stress. For most daily-use driveways and garage aprons, foam is our default recommendation.

Choose mudjacking when the budget is tight, the soil is firm, the void is shallow, the drainage problem has been fixed, and you can stay off the slab for a day or more. Sidewalks, patios and walkways on stable ground are classic mudjacking jobs, and an experienced mudjacking crew will deliver a sound repair at a lower price.

Choose neither when the slab is shattered into many pieces, heavily spalled, or near the end of its service life. Lifting will not fix any of those problems. Get a replacement quote, or, if the slab is sound but the surface is worn, consider leveling followed by a resurfacer such as those in our best concrete resurfacer guide.

Whichever method you choose, ask the contractor three things: what caused the settling and how it will be addressed, how many holes they will drill and how they will patch them, and what the warranty covers in writing. The answers tell you more about whether the repair will last than the choice between slurry and foam.