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Sinking Concrete Slab

The durability of concrete slabs is essential to the structural integrity of a home. Concrete is a durable material, but it is not immune to wear and tear. Therefore, it is important to take steps to ensure that concrete slabs remain in good condition, especially in areas subject to heavy use or extreme weather conditions. 

Sunken concrete slabs are more than a cosmetic issue. They are a safety hazard and a sign of potential foundation problems. If you notice sinking slabs on your driveway, walkway, porch, or inside your home, it’s essential to have it repaired immediately. Otherwise, you could risk serious damage to your foundation and other structural elements of your home. 

This page explains the causes and effects of sinking concrete slabs, and the concrete lifting solutions offered by BQ Basements & Concrete

What Is a Sinking Concrete Slab? 

A sinking concrete slab is a concrete surface that has lowered unevenly, creating a dip or crack. This can be a safety hazard due to tripping risks, and it can also reduce the aesthetic value of your property. 

Sinking concrete slabs show visible signs of damage, which may include: 

Sinking concrete slabs are common in various concrete structures, leading to problems, including: 

Identifying and repairing sinking concrete slabs prevents further damage, reduces safety risks, and restores the area to its original condition.  

Contact BQ Basements & Concrete at the earliest sign of concrete damage. Our expertise ensures thorough, long-term resolution of the issue. 

What Causes a Sinking Concrete Slab? 

Concrete slabs and foundations sink for various reasons, including: 

  • Settling Soil: Over time, the natural compaction and consolidation of the soil beneath the slab can lead to sinking. This phenomenon is particularly common when improperly compacted fill dirt is used, often exacerbated during dry periods. 
  • Soil Erosion: Water drainage issues, leaks, or shifts in soil can erode and wash away the supporting dirt beneath the concrete, resulting in an unstable base and subsequent sinking. 
  • Precipitation: Saturated soil due to rain and flooding or melting snow during winter storms can lead to expansion and movement, causing instability in the slab. Prolonged moisture exposure can further exacerbate erosion and weaken the soil. 
  • Inadequate Drainage: Damaged drainage systems, such as gutters and downspouts, can allow excess water to accumulate on or near the concrete, contributing to underlying soil issues. 
  • Tree Root Intrusion: Growing tree roots displace the surrounding soil, potentially lifting and cracking slabs. As these roots decompose, voids form in the soil, leading to sinking slabs. 
  • Freeze-Thaw Conditions: Repeated cycles of freezing and thawing in the ground cause expansion and contraction, placing stress on and shifting the soil beneath slabs. 
  • Installation Errors: Mistakes made during site preparation, base compaction, slab curing, and pouring can result in later sinking and cracking of concrete. 

It’s imperative to promptly address these underlying causes to prevent further structural damage to your home’s foundation. 

Can You Fix a Sinking Concrete Slab? 

Yes, fixing a sinking concrete slab is feasible and crucial, as severe damage can limit the available repair options. 

Determining the appropriate long-term solution relies on accurately identifying and addressing the underlying cause. Traditional mudjacking methods and gravel filling beneath the slab may lead to continued sinking. 

A comprehensive approach is necessary for lasting concrete repair and protection. Implementing a whole-home solution that addresses all underlying causes ensures optimal outcomes and prevents future problems. 

At BQ Basements & Concrete, we employ the SettleStop™ PolyRenewal™ Injection System, a cutting-edge polyurethane injection system designed to elevate sunken exterior concrete slabs. In cases of foundation issues, we deploy alternative methods like foundation piers—specifically tailored for slab foundations—to permanently stabilize and potentially elevate your settling foundation. 

Every residence is unique and demands its own specific repair approach. Contact the BQ team to discover the most suitable repair for your home. 

How to Fix a Sinking Concrete Slab 

When employing PolyRenewal™ for the elevation of sunken concrete slabs, BQ Basements & Concrete adheres to a precise procedure: 

  • Inspect the concrete slabs to determine the extent of the damage and the best repair method. 
  • If PolyRenewal™ is the best option, mark the affected areas and drill penny-sized holes into the concrete. 
  • Insert injection ports into the holes and secure them in place. 
  • Mix the proprietary closed-cell polyurethane foam and inject it under the slab through the injection ports. 
  • The foam expands, lifts, and returns the concrete slab to its original position. 
  • Allow the foam to cure for approximately 15 minutes. 
  • Remove the injection ports and fill and smooth out the drilled holes. 
  • Seal existing cracks and joints to prevent future damage. 
  • Implement routine inspections and maintenance to extend the lifespan of concrete slabs. 

BQ Basements & Concrete’s proprietary products are tailored to your specific needs, providing superior quality and durability than generic solutions. 

Why Address a Sinking Concrete Slab Now 

Having a sinking concrete slab professionally repaired is imperative for several reasons: 

  • Safety Concerns: Uneven or sunken slabs pose a significant risk of tripping and falling, particularly for seniors, small children, and individuals with mobility challenges. 
  • Ongoing Shifting: Without proper repairs, slabs will continue to shift and sink further, exacerbating the issue over time. 
  • Potential Structural Complications: The underlying soil problems responsible for sinking slabs can also lead to damage to walls and foundations if not promptly addressed. 
  • Water-related Complications: Sinking slabs create opportunities for water to accumulate and infiltrate beneath foundations, resulting in moisture-related damage, mold growth, and the development of cracks. Exterior issues like poor drainage, flooding, and pest attraction may also arise. 
  • Aesthetic and Property Value Impact: Cracked or uneven slabs detract from the overall visual appeal of a property and can negatively influence curb appeal. Additionally, they may deter potential buyers. 

Trust BQ Basements & Concrete as your dependable resource for concrete repair needs, whether it’s fixing sinking slabs or addressing foundation floor cracks. Our distinctive solutions are essential to fully resolve these issues, and our products offer superior, lasting results that stand out from off-the-shelf options. 

Contact BQ Basements & Concrete for Reliable Concrete Lifting Solutions 

Sinking concrete slabs can be a costly problem, but it’s one that BQ Basements & Concrete solves quickly and effectively. Our trained experts use advanced diagnostics and proprietary products to lift concrete and prevent future sinking and cracking. 

The SettleStop™ PolyRenewal™ foam injection system is a quick and precise way to lift settled slabs. We also offer comprehensive foundation repair solutions to address related foundation issues and ensure long-lasting protection for your home. 

Regardless of your needs, BQ Basements & Concrete has the solutions to keep your home safe, stable, and secure. Contact us for a free inspection and estimate.


The cost of fixing a sinking concrete slab depends on the slab’s size, the damage’s severity, and the repair methods required. We make it easy to start the process by offering free inspections, no-obligation estimates, transparent pricing, and financing options tailored to your needs.  

Contact BQ Basements & Concrete for a detailed and accurate breakdown of the costs involved for your specific project. Remember, addressing a sinking concrete slab at the first sign of trouble prevents further structural damage to your home’s foundation. 

BQ Basements & Concrete’s PolyRenewal™ foam injection process can lift settled slabs in as little as 15 minutes, making it one of the fastest and most efficient concrete repair methods available. The total project duration will vary depending on the size of the slab and the extent of the damage, but we will provide a detailed timeline estimate and help you choose the best repair solution for your needs and budget. 

Yes, our concrete lifting repair solutions are designed to withstand all weather conditions, ensuring durability and protecting foundation during winter storms, rain, flooding, and droughts. Our PolyRenewal™ polyurethane foam is water-resistant and resistant to washout and erosion, providing the concrete with lasting support and protection against the elements. Our expert team will assess your property’s needs and recommend the best repair solution. Contact BQ Basements & Concrete today to learn more about our concrete lifting and foundation repair services

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