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Sinking Concrete Slabs

Ensuring your home’s structural integrity is vital, and the stability of concrete slabs plays a crucial role in maintaining it. Unfortunately, concrete can suffer damage over time despite its durable nature. 

When you notice a sinking concrete slab on your driveway, sidewalk, porch, or inside your home, it’s more than just an eyesore. It’s a safety concern and a sign of underlying soil issues that could harm your home’s foundation if left unattended. 

At Tar Heel Basement Systems, we understand the challenges homeowners face with sinking concrete slabs, whether outdoors or indoors. We specialize in comprehensive, long-lasting solutions tailored to address and resolve these issues, enhancing your home’s safety and appearance. 

This page explains why sinking concrete slabs occur, how they affect your home, and how Tar Heel Basement Systems’ proprietary concrete lifting solutions and additional repair services can benefit you. 

What Is a Sinking Concrete Slab? 

A sinking concrete slab is when a concrete surface gradually lowers unevenly, resulting in noticeable dips or cracks. This issue not only affects your property’s aesthetics but also poses serious safety risks due to tripping hazards. 

Sinking concrete slabs can commonly occur in various structures, including: 

In addition to sinking, concrete slabs can exhibit other damage such as: 

Identifying and addressing a sinking slab early can prevent more extensive damage, mitigate risks, and restore the functionality and beauty of the area. This is why it is essential to reach out to local concrete restoration specialists such as Tar Heel Basement Systems at the first sign of concrete deterioration. 

What Causes a Sinking Concrete Slab?  

Several common factors can cause a sinking concrete slab: 

  • Settling Soil: Over time, the soil beneath the slab naturally compacts and consolidates, causing the concrete above it to sink. This often happens when fill dirt is used and not properly compacted, especially during dry periods. 
  • Eroding Soil: Water drainage issues, leaks, or shifting soil can erode and wash away the soil under the concrete, leaving it without a stable base and causing it to sink. 
  • Excessive Precipitation: Saturated soil from rain, flooding, or snowmelt can expand and move, causing instability in the slab. Long-term moisture can lead to erosion and soil weakening. 
  • Poor Drainage: Damaged drainage systems like gutters and downspouts can allow excess water to collect on or near the concrete, contributing to underlying soil problems. 
  • Tree Roots: Growing tree roots can displace surrounding soil, lifting and cracking slabs. As roots decompose, they leave voids in the soil, leading to sinking slabs. 
  • Freeze-Thaw Cycles: Repeated freezing and thawing of the ground cause soil expansion and contraction, which stresses and shifts the soil under slabs. 
  • Installation Problems: Mistakes during site preparation, base compaction, slab curing, and pouring can lead to later sinking and cracking of concrete. 

Addressing these underlying causes promptly is essential in preventing further structural damage to your home’s foundation. 

Can You Fix a Sinking Concrete Slab?  

Yes, it is not only feasible but also essential to fix a sinking concrete slab. As soon as you observe any problems, it’s vital to identify and rectify the issue promptly to prevent severe damage that could limit your repair options. 

The right long-term solution hinges on accurately pinpointing and addressing the root cause. Merely mudjacking or filling the space beneath the slab with gravel may lead to further sinking. 

A holistic approach is indispensable for a lasting repair and safeguarding the slab. A complete home solution, which tackles all underlying issues utilizing cutting-edge techniques and products, will ensure optimal results and avert future incidents. 

Tar Heel Basement Systems employs the SettleStop™ PolyRenewal™, an innovative polyurethane injection system designed to raise sunken exterior concrete slabs. Should your residence exhibit foundational problems, we will use  other strategies such as foundation piers, inclusive of slab foundation-specific slab piers, to permanently stabilize and possibly lift your settling foundation. 

Given that every home is unique with its particular repair needs, we invite you to contact our team today to pinpoint the most suitable repair solution for your home. 

How to Fix a Sinking Concrete Slab  

When using PolyRenewal™ to lift sunken concrete slabs, Tar Heel Basement Systems follows a precise process: 

  • Inspect problematic concrete slabs. 
  • Verify the need for PolyRenewal™ or other repairs. 
  • Drill small holes into the affected concrete. 
  • Affix installation ports in the holes. 
  • Mix proprietary closed-cell polyurethane foam. 
  • Inject foam under the concrete slab. 
  • Allow foam to fill the void under the slab, effectively lifting the concrete. 
  • Let the foam cure (approximately 15 minutes). 
  • Remove injection ports. 
  • Fill and smooth the drilled holes. 
  • Seal cracks and joints to prevent future damage. 
  • Regularly inspect and maintain the concrete slabs for lasting protection. 

Tar Heel Basement Systems’ proprietary products are customized to address your specific issues more effectively than generic solutions, providing unparalleled quality and durability. 

Why Address a Sinking Concrete Slab Now 

It’s crucial to have a sinking concrete slab professionally inspected and repaired for several reasons: 

  • Safety: Uneven, sunken slabs present tripping and falling risks, especially for seniors, small children, and those with mobility issues. 
  • Ongoing Movement: Slabs will continue to shift and sink without proper repairs, worsening the problem over time. 
  • Structural Damage: Soil problems that cause sinking slabs can harm walls and foundations if left unaddressed. 
  • Water Issues: Sinking slabs allow water to pool and seep under foundations, leading to moisture damage, mold, and cracks. Exterior issues include poor drainage, flooding, and attracting pests. 
  • Appearance and Property Value: Cracked, uneven slabs look unattractive and deter potential buyers. 

Tar Heel Basement Systems and our distinctive solutions are essential for fully resolving these issues. Our products offer superior, lasting results compared to off-the-shelf options. 

Contact Tar Heel Basement Systems for Reliable Concrete Lifting Solutions  

Don’t let minor issues escalate into costly repairs. If you observe any indications of sinking, settling, or uneven concrete slabs on your premises, reach out to Tar Heel Basement Systems for a complimentary inspection and quote. Our skilled professionals utilize cutting-edge diagnostic tools and exclusive products designed to elevate concrete and avert future subsidence and fractures. 

Our PolyRenewal™ foam injection method is capable of swiftly and accurately restoring settled slabs to their original position. In addition, we offer extensive foundation repair options that tackle associated foundational problems, guaranteeing long-term protection. Whatever the specific needs of your home may be, rest assured that Tar Heel Basement Systems provides top-notch solutions to safeguard its security, stability, and durability. 


Absolutely, our solutions are specifically designed to be resistant to a range of environmental conditions, from heavy rainfall and flooding to snow and drought, ensuring stability and long-term durability. Our PolyRenewal™ polyurethane foam is guaranteed to offer consistent support and will not wash away or erode from underneath the concrete. Reach out to Tar Heel Basement Authority today to find out more and schedule your complimentary inspection. 

With Tar Heel Basement Systems’ PolyRenewal™ foam injection process, settled slabs can be lifted in as little as 15 minutes. However, the overall duration of the project is dependent on the size of the slab and the degree of damage. A timeline estimate will be provided during your free inspection

The price of the project can vary based on the size of the slab, the extent of the damage, and the methods used for repair. Tar Heel Basement Systems is happy to offer complimentary inspections, obligation-free estimates, transparent pricing, and a range of payment and financing options. Get in touch with us today to find out more and receive a precise cost breakdown. 

*Disclaimer: “Concrete leveling” means the process by which cracked, uneven concrete is stabilized, and in many cases lifted, by means of PolyRenewal™ polyurethane foam. Tar Heel Basement Systems does not guarantee that PolyRenewal™ can make your concrete perfectly level.

TarHeel Basement Systems Service Map

Our Locations

Fayetteville Location

3400 Walsh Pky, Suite 220
Fayetteville, NC 28311

Greensboro Location

611 Summit Ave, Suite 5
Greensboro, NC 27405

North Raleigh

208 Millbrook Rd. Suite C
Raleigh, NC 27609

Raleigh / Durham / Chapel Hill Location

3333 Air Park Road
Fuquay-Varina, NC 27526

Wilmington Location

2155 Enterprise Dr. NE
Leland, NC 28451

Winston-salem / High Point Location

2910 Griffith Rd
Winston-Salem, NC 27103