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Concrete Leveling

Sunken and uneven concrete is a tripping hazard and an eyesore — but in most cases you do not need to replace it, you just need to lift it back up.

Concrete leveling technician injecting foam beneath a sunken driveway slab in Santa Rosa, CA

What Is Concrete Leveling and How Does It Work?

Concrete leveling is the process of raising sunken or uneven concrete slabs back to their original position without tearing them out and starting over. It is faster, cleaner, and almost always less expensive than a full replacement. If you have a section of driveway, sidewalk, patio, or pool deck that has sunk an inch or two, leveling is almost certainly the right call.

The most common method used today is called polyurethane foam injection, or polyjacking. Here is how it works: small holes are drilled through the slab, a high-density foam is injected underneath, and the foam expands to fill voids and lift the slab back into place. The holes are patched and the job is done in a matter of hours. The foam cures quickly, so you can use the surface again the same day.

Why does concrete sink in the first place? Soil erosion beneath the slab is the most common cause. Water washes away the soil that supports the concrete, leaving a void. The slab drops into that void under its own weight. Tree roots, poor compaction during the original installation, and changes in soil moisture all play a role too.

Signs Your Concrete Needs to Be Leveled

Do not wait until someone trips

Uneven concrete is more than an aesthetic problem. It is a real safety hazard, especially for children and older adults. A lip of just half an inch is enough to catch a foot and cause a fall. If you own a business, uneven concrete on your property also creates liability risk.

Here are the signs that concrete leveling might be the solution for your property:

  • One or more slabs that are visibly lower than the surrounding surface
  • A step-up or step-down at a control joint that was not there before
  • Water pooling on your driveway or patio instead of draining away
  • Gaps between the slab and the house foundation or curb
  • A rocking or hollow feeling when you walk across the slab
  • Doors or garage doors that are harder to open due to slab movement

If you notice any of these on your concrete driveway or walkways, it is worth getting an assessment before the problem gets worse.

Concrete Leveling vs. Full Replacement: Which One Do You Need?

Here is how we decide

Not every sunken slab can be saved with leveling. When we assess your concrete, we look at a few key factors to determine whether lifting it makes sense or whether concrete repair and replacement is the better path forward.

Leveling works well when the slab itself is structurally sound. If the concrete is cracked through, crumbling, or badly deteriorated, lifting it will not fix those problems. In those cases, replacement is the right move. But if the slab is in decent shape and the issue is purely that it has sunk, leveling saves you significant money and hassle.

The cost difference is real. Concrete leveling typically costs 50 to 70 percent less than a full replacement for the same area. There is also no demolition, no hauling away broken concrete, no waiting weeks for a new slab to cure, and no disruption to your landscaping. The foam-injected areas are ready for use within hours.

We will always give you an honest assessment. If replacement is truly the better value for your situation, we will tell you that — and handle it ourselves. If you want to see the full range of what we do, visit our concrete services home page.

Frequently Asked Questions About Concrete Leveling

How long does concrete leveling last?+
Polyurethane foam leveling is a long-lasting solution. The foam itself does not break down or wash away the way traditional mudjacking material can. Most lifted slabs stay in place for 10 to 15 years or longer, assuming the underlying soil conditions are addressed and water drainage is properly managed. If the original cause of sinking — like poor drainage or tree roots — is not corrected, the slab may shift again over time. We can advise you on what to watch for after the job is done.
Will the repair holes be noticeable?+
The injection holes are small, typically about 5/8 of an inch in diameter. After the foam is injected and cures, the holes are patched with a concrete-matched filler. On a plain gray slab they are barely noticeable. On decorative or colored concrete they may be slightly more visible, but we take care to blend the patch as closely as possible. The results are far less noticeable than the uneven slab was before the work.
Can you level concrete near my foundation?+
Yes. Leveling slabs adjacent to your home's foundation is one of the most important applications of this service, because gaps between the slab and foundation allow water to run toward your home. We work carefully in these areas to raise the slab back to the proper height and restore that water-shedding slope. We take extra care near foundations to avoid applying excessive pressure that could affect the structure. Give us a call and we can walk you through what to expect for your specific situation.

Got a sunken slab? We can lift it without a full replacement.

Call (707) 867-4944

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