Concrete Leveling: Mudjacking vs. Foam Jacking -- Cost, Pros, and Which to Choose

You step out your front door and notice the sidewalk has dropped half an inch. Or the garage floor has a noticeable slope toward the wall. Or a section of your driveway has settled and created a lip you catch your shoe on every morning. The concrete itself looks fine -- it is just not where it used to be.

This is one of the most common concrete problems in residential construction, and the solution does not require jackhammering everything out and pouring new slabs. Concrete leveling -- sometimes called slabjacking or concrete raising -- lifts the existing slab back to its original position by pumping material underneath it. Two methods dominate the market: traditional mudjacking and the newer polyurethane foam injection (foam jacking). Both work. They differ meaningfully in cost, longevity, weight, and suitability for different situations.

This guide covers both methods in detail so you can make an informed decision before calling a contractor.

What Is Concrete Leveling?

Concrete leveling is the process of raising a sunken, settled, or uneven concrete slab back to its original grade. Instead of removing and replacing the entire slab, a contractor drills small holes through the concrete and pumps material underneath it. The material fills voids in the soil beneath the slab, builds up pressure, and lifts the concrete back into position.

The concept is simple: something under the slab eroded, compacted, or washed away, creating a gap. Fill that gap with something stable, and the slab goes back where it belongs.

Why Concrete Settles in the First Place

Understanding why your slab dropped helps determine whether leveling will be a permanent fix or a temporary one. The most common causes:

• Poor soil compaction during construction. The builder backfilled around the foundation or under the slab with loose soil that was never properly compacted. Over time, it settles. This is the number one cause of slab settlement and the easiest to fix permanently with leveling -- once the void is filled, the problem is typically solved.
• Erosion from water. Downspouts dumping water near the slab, poor grading directing runoff under the concrete, or leaking underground pipes washing soil away. If the water issue is not corrected first, leveling is a temporary fix at best.
• Drought and soil shrinkage. Clay-heavy soils expand when wet and contract when dry. Repeated wet-dry cycles create gaps under slabs. Common in Texas, Missouri, the Southeast, and much of the Midwest.
• Tree root decay. Large tree roots that grew under or near a slab die off, leaving voids. The slab drops into the empty space.
• Organic material decomposition. Fill soil containing organic matter (topsoil, wood, debris) decomposes over time, creating voids.

Mudjacking Explained

Mudjacking, also called slabjacking or pressure grouting, has been used since the 1930s. It is the original concrete leveling method and still accounts for roughly 60% of residential leveling jobs in the U.S., primarily because of its lower cost.

How Mudjacking Works

The contractor drills holes through the sunken slab -- typically 1.5 to 2 inches in diameter. A hydraulic pump then forces a slurry mixture through those holes and into the voids beneath the slab. As the slurry fills the gaps and builds up, it pushes the slab upward. The contractor monitors the lift with a level and stops pumping when the slab reaches the target height. The drill holes are then patched with concrete.

The Slurry Mixture

The slurry is a wet mixture of cement, water, sand, and sometimes topsoil or limestone. The exact recipe varies by contractor and region. Some add bentonite clay for plasticity. The mixture has the consistency of thick pancake batter -- fluid enough to pump but heavy enough to stay in place and support weight once it cures.

Mudjacking Pros

• Lower cost. Typically 30-50% less than foam jacking for the same project.
• Proven track record. Nearly a century of use in residential and commercial applications.
• Widely available. Almost every market has multiple mudjacking contractors. Foam jacking is less available in rural areas.
• Environmentally inert. The slurry is made of natural materials -- cement, sand, soil. No chemical concerns.
• Can fill large voids. The sheer volume of material makes mudjacking well-suited for situations where significant voids exist under the slab.

Mudjacking Cons

• Heavy. The slurry weighs 100-150 pounds per cubic foot. If the underlying soil is already weak or unstable, you are adding significant weight to an already compromised surface. This can cause re-settling.
• Larger holes. The 1.5-2 inch holes are more noticeable than the 5/8-inch holes used in foam jacking, even after patching.
• Longer cure time. The slurry needs 24-48 hours to fully set. You should avoid driving or placing heavy loads on the slab during this window.
• Susceptible to water erosion. Because the slurry is cement-based and somewhat porous, it can erode if water continues to flow beneath the slab. In areas with ongoing drainage issues, the fill material can wash out over time.
• Shrinkage. Like any cement-based product, the slurry shrinks slightly as it cures and dries. This can create small gaps between the fill and the underside of the slab.

Foam Jacking Explained

Foam jacking -- also called polyjacking, polyurethane foam injection, or poly leveling -- uses high-density polyurethane foam instead of cement slurry to lift and stabilize concrete. The method was developed in the 1970s for industrial applications and moved into the residential market in the early 2000s. It has grown rapidly, particularly in metro areas where contractors can justify the higher equipment costs.

How Foam Jacking Works

The contractor drills smaller holes in the slab -- typically 5/8 inch in diameter, about the size of a penny. A specialized injection gun delivers two-component polyurethane resin through a port inserted in each hole. When the two chemicals meet, they react and expand, generating foam that fills voids and lifts the slab. The expansion is powerful -- high-density structural foam can exert thousands of pounds of lifting force per square foot. The contractor controls the lift in real time, adjusting injection points and volume with a laser level or transit.

The Foam Material

Structural polyurethane foam used in concrete leveling is not the spray foam you see in attics. It is a closed-cell, high-density material engineered for load-bearing applications. The foam used for residential leveling typically has a density of 2-4 pounds per cubic foot (compared to cement slurry at 100-150 lbs/ft3). Higher-density foams (4-8 lbs/ft3) are available for commercial and industrial applications. Once cured, the foam is rigid, waterproof, and does not break down.

Foam Jacking Pros

• Extremely lightweight. At 2-4 lbs/ft3, polyurethane foam adds virtually no weight to the underlying soil. This is a significant advantage when the soil itself is weak or compressible.
• Fast cure time. Foam reaches 90% of its structural strength within 15 minutes. You can walk on the slab immediately and drive on it within an hour in most cases.
• Smaller holes. The 5/8-inch holes are less visible and easier to patch. On decorative or stamped concrete, this matters.
• Waterproof. Closed-cell foam does not absorb water, erode, or wash away. In areas with drainage problems, the fill material itself will not degrade.
• No shrinkage. Polyurethane foam does not shrink as it cures. What you see at injection is what you get permanently.
• Precision control. The expansion rate and volume can be controlled precisely, allowing for more accurate leveling -- particularly useful on pool decks and interior floors where tolerances are tight.

Foam Jacking Cons

• Higher cost. Typically 50-100% more than mudjacking for the same project. The raw material is more expensive, and the equipment has a higher capital cost.
• Less available. Foam jacking requires specialized equipment and training. In smaller markets and rural areas, you may not find a contractor who offers it.
• Not ideal for very large voids. If there is a 6-inch gap under your slab, filling it entirely with foam can be expensive. Mudjacking is more cost-effective for filling large volumes.
• Chemical material. Polyurethane is a petrochemical product. While inert once cured, it is not a natural material. Some environmental certifications and green building standards may flag it.
• Heat-sensitive during application. The chemical reaction generates heat. In rare cases, if foam is injected near plastic pipes, conduit, or other heat-sensitive materials, there is a (small) risk of damage. Experienced contractors know to account for this.

Head-to-Head Comparison: Mudjacking vs. Foam Jacking

Here is how the two methods compare across every metric that matters. This table covers the factors contractors typically do not volunteer unless you ask.

Costs in Detail

Pricing for concrete leveling is usually quoted per slab section, per square foot, or per hole -- depending on the contractor and region. Here is what you should expect to pay in 2026 dollars.

Mudjacking Costs

Foam Jacking Costs

Vs. Full Slab Replacement

For context, here is what it costs to tear out and replace the same surfaces:

What Drives Leveling Costs Up

• Number of holes needed. More injection points mean more labor and material.
• Depth of the void. A slab that has sunk 3 inches requires significantly more fill material than one that dropped 1/2 inch.
• Access difficulty. Slabs in tight spaces, backyards with limited equipment access, or slabs surrounded by landscaping cost more to reach.
• Slab thickness. Thicker slabs (6+ inches) require more drilling time and are harder to lift.
• Minimum service charge. Most contractors have a $300-$500 minimum regardless of job size. Leveling one small sidewalk panel may cost the same as leveling three.
• Geographic region. Costs in high-cost metro areas (coastal California, NYC metro, Chicago) run 20-40% above national averages.

Common Applications

Concrete leveling works on any poured concrete slab that is structurally sound but no longer at the correct height. Here are the most common use cases and what to consider for each:

Driveways

The most common leveling project. Driveways settle where they meet the garage floor (creating a lip), at expansion joints, and where the driveway transitions to the street or sidewalk. Both mudjacking and foam work well. If the driveway section is near a downspout or area with known water issues, foam is the better choice due to its water resistance.

Sidewalks

Raised or sunken sidewalk sections are a liability issue for homeowners -- trip hazards create legal exposure. Sidewalks are among the easiest and cheapest surfaces to level because the sections are small and accessible. Many municipalities will fine homeowners for uneven sidewalks that front their property.

Pool Decks

Pool decks need to maintain proper drainage slope away from the pool. Sunken sections can direct water into the pool or create standing water where people walk. Foam jacking is strongly preferred for pool decks: the lighter weight is less likely to cause further settling, the smaller holes are less visible on decorative concrete, and the waterproof foam will not erode from pool splash or rain. Most pool deck leveling contractors will not use mudjacking for this application.

Garage Floors

Garage floors settle because the soil under the garage was often backfilled hastily during construction. A sloped garage floor is annoying (tools rolling away, water pooling) but also signals that the soil under your home may be settling too. Garage floors are a good candidate for either method, though foam's fast cure time is attractive -- you can park on it the same day.

Patios and Porches

Concrete patios and porch slabs settle where they adjoin the house foundation. This creates a gap between the slab and the house, allows water to pool against the foundation, and looks unsightly. Both methods work, but if the patio is stamped or decorative, the smaller holes from foam jacking will be far less noticeable.

Warehouse and Commercial Floors

Interior commercial floors -- warehouse slabs, factory floors, retail spaces -- settle under heavy equipment, forklift traffic, and point loads. Foam jacking dominates commercial leveling because the fast cure time means minimal disruption to operations. A section of warehouse floor can be leveled and returned to service within hours rather than days.

Steps and Stoops

Concrete steps that have pulled away from the house or settled unevenly are both a safety hazard and an eyesore. Leveling steps is trickier because the concrete is thicker and the tolerances are tighter (each step needs to be close to the same height). Foam's precision makes it the better choice for steps, though mudjacking works for simpler situations.

The Process Step by Step

Mudjacking Process

Total time on site: 1-3 hours for a typical residential job.

Foam Jacking Process

Total time on site: 30 minutes to 2 hours for a typical residential job.

How Long Does It Last?

Longevity is where the two methods diverge most significantly, and it is the primary argument for paying more for foam.

Mudjacking: 5-10 Years

A mudjacking job done on stable, well-drained soil will typically last 5-10 years. The cement slurry itself is durable, but it has two vulnerabilities: weight and water. The slurry adds meaningful weight to already-compromised soil, which can accelerate re-settling. And if water continues to flow under the slab, it can erode the slurry over time, recreating voids.

In ideal conditions (stable soil, good drainage, no ongoing water issues), mudjacking can last 10+ years. In poor conditions (clay soils, active water, tree roots), re-settling within 3-5 years is common.

Foam Jacking: 10-15+ Years

Polyurethane foam typically lasts longer for two reasons: it adds almost no weight to the soil, and it does not erode. The foam itself is permanent -- it will not break down, dissolve, or compress under normal residential loads. The slab will only re-settle if the soil beneath the foam continues to erode or shift, which the foam itself cannot prevent.

In practice, foam-leveled slabs in stable soil conditions routinely last 15-20 years. The limiting factor is the soil, not the foam.

When Leveling Works vs. When You Need Replacement

Concrete leveling is not appropriate for every situation. Here is an honest breakdown of when to level and when to tear out and replace.

Can You DIY Concrete Leveling?

The short answer is: probably not, and you probably should not try.

Why DIY Mudjacking Does Not Work

Mudjacking requires a hydraulic pump capable of generating enough pressure to lift several thousand pounds of concrete. These are commercial machines that cost $5,000-$15,000 and weigh hundreds of pounds. You also need a core drill, a slurry mixing setup, and experience knowing how much material to pump and where. Over-pumping can crack the slab. Under-pumping leaves it uneven. There is no practical DIY path here.

Why DIY Foam Jacking Does Not Work

The polyurethane foam kits marketed to homeowners (typically sold at big-box stores for $50-$200) are designed for filling small voids and cracks -- not for structural lifting. They do not generate anywhere near the pressure or volume needed to raise a concrete slab. Professional foam injection rigs cost $30,000-$60,000 and require training to operate safely. The chemicals are also hazardous before curing and require proper handling.

What You Can Do Yourself

There are legitimate DIY approaches for minor concrete unevenness:

• Self-leveling compound. For indoor slabs (garage floors, basement floors) that are slightly uneven (less than 1/2 inch), self-leveling compound poured over the surface can create a flat plane. This does not lift the slab -- it fills the low spots from above. Cost: $30-$60 per bag, each covering about 50 sq ft.
• Grinding. If one slab section is slightly higher than the adjacent one (a trip hazard at a joint), a concrete grinder can shave down the high side. You can rent a grinder for $100-$200/day. This removes material rather than adding it.
• Patching. For cosmetic issues -- small cracks, pitting, surface flaking -- concrete patch products can restore the surface appearance without leveling.

Commercial vs. Residential Leveling

While the principles are identical, commercial and residential leveling differ in several practical ways:

Commercial jobs almost always use foam jacking. The reason is simple: a warehouse that shuts down for two days while mudjacking slurry cures loses far more in downtime than the price difference between the two methods. Foam's 15-minute cure time means the floor is back in service during the same shift.

Finding a Concrete Leveling Contractor

Concrete leveling is a specialty trade, not general contracting. Here is how to find someone qualified:

• Search specifically for "concrete leveling" or "mudjacking" or "polyjacking" in your area. General concrete contractors (who pour new slabs) often do not do leveling work. These are different skill sets and equipment.
• Check that they carry liability insurance and are bonded. Concrete leveling can go wrong -- over-lifting can crack slabs, and foam injection near utilities has risks. You need a contractor with proper coverage.
• Ask about their equipment. A legitimate foam jacking contractor will own (not rent) their injection rig. If they are renting, they are likely new to the service.
• Request before-and-after photos from previous jobs. Specifically ask for jobs similar to yours (same surface type, same issue).
• Get at least three quotes. Concrete leveling quotes vary by 30-50% for the same job. Three quotes gives you a realistic range and helps identify outlier pricing.
• Verify they assess the cause of settlement. A contractor who lifts the slab without discussing drainage, soil conditions, or what caused the problem is setting you up for a callback.

Questions to Ask Before Hiring

Use this checklist when interviewing concrete leveling contractors. The answers will tell you a lot about their expertise and whether they are the right fit for your project:

1. What method do you recommend for my situation, and why? A good contractor explains the trade-offs and recommends based on your conditions, not just what they have equipment for.
2. What do you think caused the settlement? If they cannot answer this, they are not assessing the problem properly.
3. Will this fix the problem permanently, or should I expect re-settling? Honest contractors will tell you if the underlying cause is still active.
4. How many holes will you need to drill? This affects both cost and the appearance of the finished product.
5. What is your warranty? Standard warranties range from 1-5 years for mudjacking and 3-10 years for foam. No warranty is a disqualifier.
6. What does the warranty actually cover? Some warranties only cover the fill material, not re-settling from soil movement. Others exclude "acts of nature" (which can include drought). Read the language carefully.
7. Can you provide references from jobs completed at least 2 years ago? Recent references only prove the slab was level on day one. You need to know it stayed level.
8. What happens if the slab cracks during lifting? It is uncommon but not impossible. Know the policy before it happens.
9. Do you have before-and-after photos of similar projects? Competence shows in the portfolio.
10. What is your minimum service charge? If you are leveling one small sidewalk section, the minimum charge may exceed the per-square-foot rate.

Warranty Differences

Warranties in the concrete leveling industry are not standardized. What you get depends on the contractor, the method, and (critically) the fine print.

Mudjacking Warranties

Most mudjacking contractors offer a 1-3 year warranty. Some offer up to 5 years on select projects. The warranty typically covers the fill material and workmanship but excludes settlement caused by new soil movement, drainage changes, or "natural causes." Because mudjacking has a shorter expected lifespan and the fill material is susceptible to erosion, contractors are conservative with their guarantees.

Foam Jacking Warranties

Foam jacking warranties are generally stronger: 3-5 years is standard, with some contractors offering 10 years or even lifetime warranties on the foam material. The foam itself is essentially permanent, so contractors can back it more confidently. However, the same exclusions apply for soil movement -- if the ground under the foam shifts, the warranty may not cover re-leveling.

What to Look For in a Warranty

• Is it transferable? If you sell the house, can the warranty transfer to the new owner? This adds real value at resale.
• What is excluded? "Acts of nature," "soil movement," and "drainage changes" are common exclusions that effectively gut the warranty. If your area has active soil (expansive clay, water table fluctuations), these exclusions may render the warranty nearly worthless.
• Is there a deductible? Some warranties require you to pay a service call fee ($100-$300) for warranty claims.
• Is the company likely to be around? A lifetime warranty from a two-person operation that has been in business for 18 months is not the same as a 5-year warranty from a company with a 20-year track record.