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Uneven Concrete2026-11-03T09:22:39-06:00

Uneven Concrete: Sidewalks, Driveways & Patios Explained in [Target Location], VA

If part of your sidewalk has dropped, your driveway has stopped sitting level, or your patio is starting to slope, the concrete itself may not be the issue. More often than not, the soil underneath it has settled, shifted or washed away, causing the slab to become uneven. Over time, that can create trip hazards, drainage problems and continued settlement. If the slab is still in good shape, professional concrete lifting can often restore it without the cost or disruption of replacement.

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Symptoms

Warning Signs Your Concrete Needs Repair

Uneven concrete almost never happens overnight. You'll often first notice a small lip between two sidewalk slabs, a section of driveway that has settled or water collecting where the surface once drained properly. When soil movement continues, those changes tend to become more noticeable. Catching the warning signs early can help you repair the existing concrete before the problem becomes more severe.

Uneven sidewalk slabs
Raised or settled driveway sections
Sloped or uneven patios
Standing water after a rain
Widening or cracked joints
Gaps between adjacent slabs
Trip hazards

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Causes

Why Does Concrete Become Uneven?

Concrete doesn't typically become uneven just because of its age. It relies on stable, well-supported soil beneath it. When the soil settles, erodes, expands, contracts or was never properly compacted during construction, the slab can lose support and begin to shift. Understanding why the concrete moved is the first step toward choosing the right repair solution.

  • Soil Settlement

    Soil can compact over time, particularly when fill soil was placed beneath the concrete during construction. As the soil settles, the concrete above it can drop.

    It often happens unevenly. One part of a slab may have plenty of support while another section sinks into softer or more compacted soil. That’s why you may see a sidewalk, driveway or patio sink in just one area.

  • Inadequate Soil Compaction

    Before a slab is poured, the soil underneath it needs to be properly prepared and compacted. If that step wasn’t done thoroughly, the soil can compress later beneath the weight of the concrete.

    The slab may look fine when it’s first installed, then gradually settle as the ground underneath it changes.

  • Water Washing Out Soil

    Water can find its way under concrete and carry soil along with it. Over time, that can leave voids beneath the slab.

    Once part of the concrete is no longer fully supported, it can sink into the space below. Drainage issues, runoff and water moving through cracks or joints can all contribute to this type of erosion.

  • Freeze-Thaw Cycles

    Freezing temperatures also affect the soil beneath concrete. Water in the soil expands as it freezes, then contracts again as it thaws.

    A single freeze/thaw cycle may not create a noticeable problem, though repeated seasonal changes can contribute to movement, particularly when other soil or drainage problems are already present.

  • Drainage Problems

    Water needs a place to go. When the drainage around a driveway, sidewalk or patio isn’t working properly, water can collect around or beneath the concrete instead of flowing away.

    Over time, excess moisture can soften the supporting soil, leave unstable conditions beneath the slab and contribute to settlement. It also increases the risk of erosion and freeze-thaw damage.

Why Ignoring Uneven Concrete Costs You

  • Minor Settlement Turns into a Safety Hazard

    Uneven concrete often starts with a small lip between slabs or a slight slope that’s easy to overlook. As that height difference grows, it can create trip hazards across sidewalks, walkways, patios and driveways.

  • Water and Soil Problems Get Worse

    As the concrete continues to settle, drainage patterns change. Water can pool in low spots or seep beneath the slab, washing away more soil and increasing seasonal freeze-thaw movement. Without stable support beneath it, the concrete is likely to continue shifting.

  • Small Repairs Can Become Bigger Projects

    What starts as a section of uneven concrete can grow into a larger repair if settlement continues. Tackling the problem early often makes it possible to lift and level the existing slab, while waiting can lead to additional movement, more extensive repairs or the need for replacement if the concrete becomes too damaged.

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NV Waterproofing and Foundation Repair's Repair Solution for Uneven Concrete

Uneven concrete is often repaired by restoring the support beneath the slab rather than replacing the concrete itself. With proven concrete repair solutions, NV Waterproofing and Foundation Repair raises settled slabs, stabilizes the supporting soil and helps protect the concrete from future water intrusion. The result is a safer, more level sidewalk, driveway, patio or other concrete surface with lasting performance and minimal disruption.

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  • PolyLevel® Concrete Lifting

    PolyLevel® uses expanding polyurethane foam to fill the voids beneath uneven concrete, stabilize the soil below and precisely lift settled slabs. The repair is minimally invasive, cures quickly and is often ready for normal use the same day.

  • NexusPro® Joint & Crack Sealant

    After concrete is lifted, sealing joints and cracks helps protect the repair from water intrusion. NexusPro® is a flexible, UV-resistant sealant built to keep water from washing away the supporting soil beneath sidewalks, driveways, patios and other concrete surfaces, helping lower the risk of future settlement.

How It Works

The Concrete Lifting Process

Step 1

Free Inspection & Customized Plan

Inspection & Tailored Plan|Free Inspection & Personalized Plan}

Every project starts with a thorough inspection of the concrete and the supporting soil. We’ll identify what’s driving the settlement, explain your repair options and recommend the best solution for your property.

Step 2

Precise Foam Injection

Small, penny-sized holes are drilled into the settled concrete, allowing PolyLevel® polyurethane foam to be injected beneath the slab without removing the existing concrete.

Step 3

Fill Voids & Stabilize the Soil

The expanding foam works into empty spaces beneath the slab and brings back the support the concrete has lost, which helps stabilize the underlying soil.

Step 4

Lift & Level the Concrete

As the foam expands, it gently raises the settled concrete back toward its original position, producing a safer, more level surface.

Step 5

Quick Cure & Ready to Use

PolyLevel® cures quickly, allowing most sidewalks, driveways, patios and other concrete surfaces to be used again the same day.

Benefits

Why Homeowners Rely On NV Waterproofing and Foundation Repair

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What To Expect

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Don't just take our word for it

See what our customers have to say about our work.

NV Waterproofing was extremely responsive and 100% committed to identifying our water problem and designing a solution. Their work was excellent. The crew was on time and organized. They were very careful to protect the exterior landscaping and the interior of our home from dirt and debris. Even two years later, they responded to a sump problem at no additional charge. NV Waterproofing does the job right and stands behind its work.

Mike and Lynn F. | Columbia, MD

We bought a house in a state of disrepair, and so we've had to work with a number of contractors. I'd rank this company at the top of the list for their professionalism, knowledge, experience, and honesty. We had bowing of our basement walls that needed to be addressed. Michael came out to assess the situation, and gave us some options. After speaking with him, I felt very confident in their ability to buttress our walls. It was also a huge bonus that we were able to set up a payment plan for this job too. When the team showed up, Casey, Kevin, and Grant, they were super polite and professional. They took great care of our property, and if they had a question about anything, they asked. Also, if I had a question, Casey (the foreman), was very knowledgeable and quick to answer. They presented the work as they progressed through the job, and really, I was actually a little blown away by the scale of the project, and the speed at which they worked. What an impressive job they did! We're very confident in the work they did and will hire them again.

Ellen M.  | Takoma Park, MD

We were referred to NV Waterproofing from my brother-in-law who used them and was pleased. They came out and gave us an estimate - they were very prompt. We had the work done - it looked great and I am sure will do the job (only time will tell). We did have a miscommunication with the work (mostly on our part), but the owner had it fixed promptly and without additional cost. I would highly recommend them to anyone with water issues in their basement.

Susan C. | Washington DC, DC

NV stuck with me and made sure I was happy. Roberto Jr kept me calm as my problem persisted and kept working on a solution beyond the obvious. I highly recommend. Looking forward to a dry basement this summer.

Dean R. | Washington, DC

I am writing this letter to commend members of your organization for the waterproofing work performed on and around the foundation of my house. Despite situations beyond the control of both me and your associate, he always maintained professionalism and demonstrated why he is an outstanding representative of your organization. The crew obviously knew what had to be done and went about doing it. They were prompt in arriving at work each day, diligent in the performance of their duties (in spite of high heat and humidity), and took measures to ensure the safety around the excavated area (important because of children in the neighborhood). Unlike other construction sites I have seen, the crew maintained the area free of litter— no small measure these days! In addition, the crew always provided clear explanations of the work to be done each day, answering the questions with forthright and clear responses, never hurrying the discussion. As I was not on site while work was being done, they called me several times, taking those extra steps to keep me informed of the status of the work and aware of the tasks yet to be performed— something that is greatly appreciated. I would appreciate it if you would offer my heartfelt thanks to your able crew for the quality waterproofing work performed and the excellent communication and coordination exhibited by them.

Myra L. | Washington, DC

In my 12 years of having NV Waterproofing as a business partner, they have always proved reliable and trustworthy. They are a great value for me and my customers.

Darryl O. of Brookfield Homes, | Washington, DC

Great professional service and able to respond in timely manner to the project need.

Blake B. | Washington, DC

Brendan was very knowledgeable, professional and courteous. Highly recommend.

Cesar T. | Arlington, VA

A brief note to thank NV Waterproofing for extreme professionalism and courtesy in the manner in which my recent basement water seepage problem was addressed. From the initial contact with Jim, through the work with Roberto, Carlos and Jose, it was an overall pleasant experience – not to mention my contact with the owner and his responsiveness.

Ramesh T. | Arlington, VA

These guys were amazing. The initial visit was smooth, not pushy at all and he was even able to accommodate the relocation of a small drainage pipe. The demo to install the system was done beautifully, yes it was really good, you can tell they were precise and careful when doing so. Everything was clean, no stains on my carpet and they protected everything. No leak so far and I love it. Did I mention the price was excellent? I had 3 other companies to estimate thousands and even tried to sell extra unnecessary equipment. Thank you NV Waterproofing I have and will continue to recommend you.

Chelly Z. | Falls Church, VA

We appreciated NV Waterproofing's honesty and the men who worked tirelessly in uncomfortably cold weather. We've had one big storm since they finished and the basement walls are nice and dry. Nice work!

Peter V. | Falls Church, VA

Mauricio and Cristian were the initial sales reps who came to examine the issue and they took the time to test drainage that might have potentially been creating the water issue. They offered a reasonable solution (sealing the visible cracks and holes in the concrete) and I was contacted within a couple of days with an estimate and scheduling options. Sean was our tech and he did a fantastic job diagnosing the issue beyond just the cracks. He not only address all the holes and cracks in the concrete and mortar, he sealed up additional entry points above the foundation. He sourced additional materials to cover openings for cable lines. He went above and beyond and gave us measured information on how we should continue to monitor and treat this area as the house settles. He was thorough, informative, and provided excellent service in his work. I'm very glad that Sean was the technician sent to us and I would specifically request him for your projects.

Sara T. | Falls Church, VA

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Before & after photos

Check out before and after photos from some of our completed projects.

  • Sunken Concrete Step Repair in Stephens City, VA

    This Stephens City, VA homeowner was dealing with a sunken concrete front step that had settled over time, creating an uneven entryway and a noticeable tripping hazard near the front door. Sunken concrete steps can make everyday foot traffic unsafe for homeowners, guests, and delivery drivers, while also taking away from the home’s curb appeal. Our concrete repair team lifted and leveled the front step back to its proper position, creating a safer, more stable walkway and entrance. This concrete step repair helped reduce the risk of falls, improved the look of the front entry, and gave the home a cleaner, more welcoming appearance. The homeowner was thrilled with the outcome — a big transformation that improved both safety and curb appeal!

  • Basement Waterproofing in Winchestor, VA

    A homeowner in Winchester, VA, was struggling with a failing sump pump that couldn’t keep up during heavy rainstorms, leaving their basement vulnerable to water intrusion. The lack of a reliable backup system also left them worried about potential flooding during power outages. Frustrated and seeking a dependable solution, they contacted NV Waterproofing and Foundation Repair, a trusted basement waterproofing company in Winchester, VA.

    After assessing the situation, we replaced their old sump pump with a state-of-the-art TripleSafe Sump Pump system. This advanced system includes three levels of protection: a primary pump, a secondary pump for heavy water flow, and a battery backup to ensure the basement stays dry even during power outages. The homeowner now has peace of mind knowing their basement is fully protected, no matter the weather.

  • Pool Deck Leveling in Manassas, VA

    A homeowner in Manassas, VA, quickly realized their dream backyard pool was at risk when the surrounding concrete pool deck began to show serious problems. Uneven and sunken slabs created tripping hazards and unsightly cracks, making both safety and aesthetics a challenge for anyone using the space. Additionally, water from rain and pool use was pooling in low spots, causing slippery surfaces and further soil erosion beneath the deck. These issues not only threatened the safety of family and guests but also compromised the value and enjoyment of the home.

    Seeking an effective solution, the homeowner reached out to our team for a professional assessment. We identified the main cause of settlement: soil erosion under the slabs—a common issue in Manassas due to its clay-rich ground and fluctuating moisture. To address both the immediate hazards and prevent future damage, we recommended our two-part approach: the cutting-edge PolyLevel® concrete leveling system and NexusPro® Joint Sealant.

    The repair process began with drilling small holes into the affected concrete slabs, allowing us to inject high-strength PolyLevel® polyurethane foam beneath the surface. As the foam expanded, it filled voids, stabilized the soil, and gently lifted the slabs back to their original positions. The process was quick, clean, and minimized disruption, giving the pool deck a level, safe surface once again. PolyLevel® foam is waterproof and lightweight, reducing the risk of future settling and ensuring long-term durability, even in a wet poolside environment.

    To provide further protection, we sealed all cracks and joints with NexusPro® Joint Sealant. This flexible, weather-resistant sealant prevents water from seeping beneath the slabs, protecting the soil and concrete from additional erosion. The result was a clean, finished appearance that not only improved the look of the deck but also safeguarded it for years to come.

    Thanks to modern concrete leveling technology, the homeowner’s pool deck was transformed from a liability into a safe and attractive outdoor gathering space. The project was completed in a single day, with minimal mess and immediate results, giving the homeowner peace of mind and renewed pride in their backyard. If you’re facing similar issues with your pool deck in Manassas, VA, the PolyLevel® system and NexusPro® Joint Sealant offer a fast, effective, and lasting

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Proudly Serving Northern Virginia, D.C., and Suburban Maryland

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Frequently Asked Questions

Can every uneven slab be lifted? 2026-10-02T11:33:44-05:00

Not all slabs are good candidates for lifting. Concrete that is severely cracked, crumbling or structurally damaged may need replacement. During an inspection, a specialist assesses both the slab and the soil beneath it to determine whether lifting is appropriate. 

Why does only a section of a concrete slab sink? 2026-10-02T11:33:17-05:00

Concrete often settles unevenly because soil conditions can vary beneath the same slab. One area may remain supported while another loses soil through settlement, erosion or poor compaction, leaving only part of the sidewalk, driveway or patio to sink. 

How long does concrete lifting hold up? 2026-10-02T11:32:48-05:00

Polyurethane foam lifting is intended as a long-term repair because it fills voids and restores support beneath the slab. How long it lasts also depends on drainage, future soil movement and the condition of the concrete. Fixing water problems around the repaired area can help protect the supporting soil from additional erosion. 

Will uneven concrete continue to get worse? 2026-10-02T11:32:22-05:00

It can, yes. If the soil beneath the concrete keeps settling, washing away or changing with moisture, the slab may continue to move. Water is especially important to watch. If it is getting beneath the concrete, it can continue eroding the soil and create larger voids beneath the slab. Drainage and soil conditions should be reviewed when determining whether the problem is likely to progress. 

What does uneven concrete repair cost? 2026-10-02T11:31:53-05:00

The price depends on the size of the affected area, how much the concrete has settled, the condition of the slab and which repair method is needed. That’s why a single price for uneven concrete repair doesn’t exist. A specialist can assess the concrete and the soil conditions and provide pricing based on the work your property actually needs. When the existing concrete can be lifted, the cost is often lower than removing the old concrete and installing a completely new slab. 

How dangerous is uneven concrete? 2026-10-02T11:31:21-05:00

Uneven concrete can create a trip hazard, above all on sidewalks, walkways, patios and steps. It doesn’t take a large raised edge to catch someone’s foot. It can also raise accessibility concerns and potential liability issues around frequently used areas of the property. If concrete has noticeably shifted, it’s worth having the area evaluated to understand whether the movement is likely to continue. 

Can uneven concrete be fixed without replacing it? 2026-10-02T11:30:42-05:00

Yes. Uneven concrete can often be lifted and leveled without replacement if the slab is still structurally sound. Polyurethane foam lifting fills the voids beneath the concrete, restores support and raises the settled section back toward level. This is often a more cost-effective and less disruptive option than replacing the entire section. Replacement may be necessary if the concrete is severely cracked, damaged or otherwise unsuitable for lifting. An inspection will help determine which approach makes sense. 

What causes uneven concrete? 2026-10-02T11:30:09-05:00

Uneven concrete usually comes down to changes in the soil beneath the slab. Soil settles or compresses, water washes soil away, and moisture changes can cause some soils to expand and contract. Freeze-thaw cycles can add to that movement. Poor soil compaction, drainage problems, heavy vehicle traffic and sometimes tree roots can also play a role. The concrete itself is usually still in usable condition, the real problem is that it has lost some of the support it once had underneath it. 

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