703-722-8580
Concrete Cracks & Gaps2026-11-02T15:46:11-06:00

Concrete Cracks & Gaps in [Target Location], VA: What Causes Them & How to Fix Them

Cracks and gaps across driveways, sidewalks, patios, porches and other concrete surfaces are common, though they shouldn't be dismissed. While certain cracks are nothing more than normal concrete curing, others are a sign that the soil beneath the slab has settled, shifted or washed away. When concrete loses support, it can crack, separate or become uneven. During a free inspection, NV Waterproofing and Foundation Repair pinpoints the underlying cause and recommends the right solution.

<a id="Symptoms">

Symptoms

Warning Signs Your Cracks Need a Professional

Concrete cracks can appear in many forms, from small hairline cracks to widening gaps between slabs. While some are simply the result of normal aging, the following warning signs often indicate the concrete is continuing to move because the supporting soil has shifted or settled.

Widening Concrete Cracks
Misaligned Concrete Slabs
Separating Concrete Slabs
Standing Water on Concrete
Trip Hazards in Concrete
Sunken Driveways, Sidewalks or Patios

<a id="Causes">

Causes

Why Do Concrete Cracks & Gaps Happen?

Concrete naturally forms small cracks over time, but not every crack has the same cause. Some result from normal curing or decades of exposure to the elements. Others appear because the soil supporting the slab has shifted, settled or washed out, letting the concrete move. Knowing what's driving the damage is the key to choosing the right repair. Although minor surface cracks are often harmless, widening cracks, growing gaps or uneven concrete often point to underlying problems that should be professionally evaluated.

  • Expanding or Shrinking Soils

    Fluctuating soil moisture can cause the ground beneath concrete to expand when wet and contract when dry. As the soil moves, the concrete loses consistent support, increasing the likelihood of cracks, gaps and settlement.

    Plenty of regions have clay-heavy soils that expand when they absorb water and contract as they dry out. This continual cycle strains concrete slabs, leading them to shift over time. Even gradual shifting can produce widening cracks or uneven surfaces if it isn’t addressed.

  • Improperly Compacted Soil

    Concrete performs best when it’s supported by properly compacted soil. If the ground wasn’t adequately prepared before the slab was poured, it may settle over time, leaving sections of concrete without the support they need.

    Poor compaction is common beneath driveways, sidewalks, patios and porches, especially where fill soil was added during construction. When loose soil compresses, the slab may crack, settle or pull away from adjacent concrete.

  • Washout and Erosion Under Slabs

    Soil erosion happens when water slowly carries away the soil supporting a concrete slab. As the supporting soil disappears, the concrete may sink, crack or separate from adjacent slabs.

    Poor drainage, leaking downspouts, heavy rain and water running beneath the slab can all contribute to soil erosion. As those voids expand, the concrete starts to settle into the empty space, leading to cracks, uneven slabs and widening gaps.

  • Seasonal Freeze-Thaw Cycles

    Water that seeps into cracks or the surrounding soil expands when it freezes and contracts as it thaws, putting additional stress on the concrete.

    Recurring freeze-thaw cycles can make existing cracks grow and drive soil movement beneath the slab. Over time, this seasonal expansion and contraction can accelerate settlement and make concrete damage more noticeable.

  • Heavy Vehicle Loads

    Repeated heavy loads can put more stress on concrete than it was built to handle, especially when the supporting soil has already weakened.

    Driveways handling large trucks, RVs or commercial vehicles may show cracking or settlement earlier than lightly used surfaces. If the soil under the slab is unstable, the extra weight can accelerate movement and worsen existing damage.

  • Natural Curing and Age of Concrete

    Hairline cracks are a typical part of concrete curing and aging. That said, cracks that continue to widen, open into gaps or turn uneven often signal movement beneath the slab rather than normal wear.

    Not all cracks signal a structural problem. However, cracks that keep widening, form gaps or come with uneven concrete often suggest the slab is moving rather than simply aging. A professional inspection can determine whether the damage is cosmetic or caused by underlying settlement.

Why Ignoring Concrete Cracks Leads to Bigger Problems

  • Stage 1

    Water Works Its Way In

    Small cracks often seem cosmetic at first, but they let water travel down to the soil beneath the slab. As moisture washes away supporting soil or causes it to expand and contract, the concrete can continue to shift.

  • Stage 2

    Uneven Slabs & Trip Hazards Develop

    When the supporting soil continues to settle or erode, sections of concrete can shift out of level or separate from one another. What started as a simple crack can become a trip hazard, collect standing water and make driveways, sidewalks, patios or porches more difficult to use safely.

  • Stage 3

    Repairs Get More Extensive

    Ignoring ongoing slab movement can lead to larger cracks, continued settlement and more expensive repairs. Handling the problem early can often stabilize and restore the concrete before heavier damage—or even replacement—becomes necessary.

<a id="Solutions">

The Way NV Waterproofing and Foundation Repair Fixes Cracked Concrete

Not every concrete crack requires the same repair. During a free inspection, NV Waterproofing and Foundation Repair determines what's causing the damage before recommending a solution. If the slab has settled, PolyLevel® is first used to lift and stabilize the concrete. With the slab properly supported, NexusPro® seals the cracks and joints to help prevent water intrusion and protect the repair.

Schedule an Estimate

  • NexusPro® Joint & Crack Sealant

    NexusPro® fills and seals concrete cracks and joints to help keep water away from the soil beneath the slab. Unlike many store-bought fillers, it stays flexible through seasonal expansion and contraction for a longer-lasting seal.

  • PolyLevel®

    When slab settlement caused the cracks, PolyLevel® lifts and stabilizes the concrete before sealing. Fixing the underlying cause helps deliver a longer-lasting repair.

How It Works

NV Waterproofing and Foundation Repair's Concrete Crack Repair Process

Step 1

Free Home Evaluation

Every project starts with a thorough inspection to identify what’s causing the cracks or gaps. If slab settlement is contributing to the damage, NV Waterproofing and Foundation Repair may recommend stabilizing the concrete with PolyLevel® before sealing the cracks.

Step 2

Grind, Route & Prepare the Joints

The cracks and joints are carefully cleaned, routed and prepped by removing dirt, debris, vegetation and old sealants. Thorough preparation helps create a strong bond for a longer-lasting repair.

Step 3

Add Flexible Backer Rod (When Needed)

For bigger or deeper cracks and joints, a flexible foam backer rod is placed before sealing. This helps control the depth of the sealant and improves the long-term performance of the repair.

Step 4

Apply the NexusPro® Joint & Crack Sealant

NexusPro® is professionally installed to fill cracks and joints, creating a flexible, watertight seal that helps keep water from reaching the soil beneath the slab. Unlike typical caulks, it resists UV exposure, shrinking and cracking over time.

Step 5

Detail & Finish the Work

The sealant is precisely tooled and finished to deliver a clean, professional look while ensuring the crack or joint is fully sealed. When the work is done, your concrete is better protected from water intrusion and future deterioration.

Benefits

Why Local Homeowners Trust NV Waterproofing and Foundation Repair

Body Copy Specific to Each Dealer

<a id="What To Expect">

What To Expect

Ready to get started?

Schedule a free estimate to start your repair journey with Thrasher.

Schedule your inspection

Fill out our form or give us a call to book your inspection. Share what you’ve noticed so we can send the right expert to your home.

Full home
inspection

An expert will inspect the problem area and surrounding conditions, including soil movement, drainage, structural integrity, and any related concerns.

Clear explanation
of findings

We’ll walk you through what we’re seeing in easy-to-understand language so you know the root cause of the issue, not just the symptoms.

Review recommendations

If repairs are needed, we’ll outline your options, pricing, and timeline so you can make the best decision for your home.

Schedule your free inspection—

It'll only take
a minute

Meet with a trusted expert, and get
clear answers about your home.

"*" indicates required fields

1Your Info
2Schedule Your Inspection
3Review & Submit

Customer Information

<a id="Testimonials">

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

<a id="Before & After Photos">

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

View all before & afters

Our service area

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

<a id="FAQs">

Frequently Asked Questions

Does store-bought concrete crack filler work permanently? 2026-10-02T11:53:11-05:00

Store-bought crack fillers can improve how concrete looks and help seal out water, but they don’t address the underlying cause of many cracks. If soil movement or washout is causing the slab to settle, the concrete may continue to move even after the crack is filled. A professional inspection can tell whether sealing alone is appropriate or whether the slab needs to be stabilized with PolyLevel® before the crack is repaired. 

What does concrete crack repair cost? 2026-10-02T11:52:42-05:00

The price depends on a few factors, including slab size, the extent of settlement, the number of cracks and the repairs needed. Since every property is different, the most accurate estimate comes from a free professional inspection. NV Waterproofing and Foundation Repair will assess the condition of your concrete and recommend the most effective repair for your situation. 

How long will concrete crack repair last? 2026-10-02T11:52:13-05:00

Lasting results depend on correcting the underlying cause of the damage. When settled concrete is stabilized with PolyLevel® and cracks are sealed with NexusPro®, the repair is designed to provide lasting performance. During your inspection, NV Waterproofing and Foundation Repair will recommend the right solution based on your property’s specific conditions. 

How does PolyLevel® fix cracked concrete? 2026-10-02T11:51:46-05:00

PolyLevel® is a high-density polyurethane foam injected under settled concrete through small, penny-sized holes. As the foam expands, it fills soil voids and gently raises the slab back toward its original position while providing long-term support. If settlement caused the cracks, stabilizing the slab helps address the underlying problem before the cracks are sealed. 

Do concrete cracks continue to spread? 2026-10-02T11:51:19-05:00

They can, yes. Once cracks let water reach the soil beneath the slab, erosion and settlement can continue, pushing the concrete to shift further. Over time, small cracks can become larger, gaps may widen and uneven concrete can create trip hazards. Correcting the underlying cause early can help prevent further damage. 

When do driveway or sidewalk cracks become a problem? 2026-10-02T11:50:53-05:00

Small hairline cracks typically come with normal concrete aging. However, if cracks continue to widen, gaps form between slabs, one section becomes higher than another or the concrete begins to sink, it’s a good idea to have it inspected. These signs often indicate ongoing soil movement that can worsen if left untreated. 

Is it possible to repair cracked concrete without replacing it? 2026-10-02T11:50:26-05:00

In many cases, yes. Plenty of cracked concrete slabs can be repaired without the expense and mess of replacement. If the slab is structurally sound, it can often be lifted and stabilized with PolyLevel®, then sealed with NexusPro® to help reduce water intrusion and protect the repair. Replacement is usually only necessary when the concrete is too damaged to restore. 

Does cracked concrete indicate foundation problems? 2026-10-02T11:49:41-05:00

Not usually. Most cracks in driveways, sidewalks, patios and other exterior concrete slabs are caused by soil movement beneath the concrete—not foundation damage. However, if you’re seeing widespread settlement around your property or cracks in both your concrete and your home’s foundation, it’s worth scheduling a professional inspection to identify the cause. 

What causes concrete cracks and gaps? 2026-10-02T11:49:10-05:00

Concrete can crack for a number of reasons, including normal curing, age, heavy loads and seasonal weather changes. However, many widening cracks and gaps develop because the soil beneath the concrete settles, shifts or washes away over time. As the slab loses support, it can crack, separate or become uneven. A professional inspection can tell whether the damage is simply cosmetic or caused by soil movement below. 

Related pages

Service Areas

NV Waterproofing has locations throughout Northern Virginia, D.C., and Suburban Maryland.

Resources

Access valuable resources to help keep your home healthy and your family safe.

Our Promise

At NV Waterproofing, we pride ourselves on providing permanent solutions, and stand behind our work with industry-leading, fully transferable warranties and guarantnees.

Schedule your free inspection today

Don’t let unanswered questions about your
home worry you any longer.
Go to Top