Concrete leveling and slab lifting in St. Louis is a fast, cost-effective repair for sunken driveways, patios, and walkways that have settled into the soft loess and clay soils beneath the city and county. St. Louis sits on silty, compressible ground over limestone bedrock, and decades of freeze-thaw cycles, clay-mine fill in older neighborhoods, and river-bottom soil near the Meramec and Missouri have left many residential slabs uneven and tripping hazards. Rather than tear out and replace an entire driveway or patio, we inject expanding foam or controlled grout beneath the settled slab to lift it back to grade, restoring safety and drainage in a single day. This method works for the narrow rear garage pads and alley parking spaces common in Soulard and the Central West End, the wide suburban driveways of Kirkwood and Chesterfield, and the front walks with stoop steps found throughout St. Louis Hills and Tower Grove South.
Why Concrete Leveling and Slab Lifting Matters in St. Louis
St. Louis concrete fails and settles faster than in most regions because of the underlying geology and climate. The silty loess and clay that make up the topsoil compress and shift as water drains away or soil consolidates under the weight of a slab. Freeze-thaw cycles in winter crack and heave concrete, while spring thunderstorms and the region's heavy rains saturate the ground beneath patios and driveways. Karst sinkholes in parts of the region and old clay-mine fill in neighborhoods like Gravois Park create unpredictable voids. A driveway or patio that was level in 1985 may have sunk 2 to 4 inches by 2020, creating trip hazards, poor drainage that pools water and accelerates decay, and an unsightly slope that catches the eye of every visitor.
- Settling and sinking slabs create trip hazards and liability risk on residential properties across St. Louis and St. Charles County.
- Poor drainage from sunken concrete allows water to pool and freeze in winter, deepening cracks and accelerating deterioration.
- Leveling restores a driveway or patio to safe grade without the cost and disruption of full replacement.
- A lifted slab improves curb appeal and drainage, extending the life of the concrete and protecting the foundation.
Addressing a settled slab early prevents bigger repairs down the road and keeps walkways and driveways safe for family, guests, and delivery crews.
Key info: In neighborhoods like Lafayette Square and Benton Park, where Victorian-era rowhouses sit on tight city lots, settled rear patio slabs and narrow alley pads are routine. Leveling these surfaces restores safe access without the cost and mess of full replacement, and the job is done in hours, not days.
For more information on concrete repair options, see our concrete repair and resurfacing page.
How We Lift and Level Concrete Slabs in St. Louis
Concrete leveling uses two proven methods to raise a settled slab back to grade. Polyurethane foam injection is fast, lightweight, and leaves no mess; hydraulic grout injection offers greater precision and is ideal for larger slabs or those with heavy traffic. Both methods start with a site assessment to identify the cause of settlement, measure the depth of sag, and locate underground utilities. We drill small ports through the concrete, inject the lifting material in stages, and monitor the slab as it rises. Once level, we seal the injection ports and restore drainage. The entire job typically takes 4 to 8 hours for a standard driveway or patio, and the concrete is ready for use the same day.
- We assess the settled slab on site, identify the root cause of settlement, and measure the depth and extent of the sag.
- We locate and mark underground utilities, gas lines, and electrical conduit to ensure safe drilling and injection.
- We drill injection ports at precise intervals across the sunken area, using a controlled process to avoid cracking the concrete.
- We inject expanding foam or controlled grout in stages, lifting the slab gradually and monitoring for level and stability.
- We seal all injection ports, restore surface finish, and verify drainage slope to prevent future ponding.
This step-by-step approach ensures the slab rises evenly and stays level, and it avoids the disruption and expense of removal and replacement.
Local example: A homeowner in Webster Groves had a 20-by-12-foot patio that had settled 3 inches at one corner, creating a noticeable slope and a tripping hazard near the back door. We injected polyurethane foam beneath the low corner in three stages, raising it to match the rest of the patio. The job took 6 hours, and the patio was ready for use the next morning. No digging, no mess, and the concrete was preserved.
If you're interested in a new patio or driveway instead, explore our concrete patios page or concrete driveways page.
Concrete Leveling and Slab Lifting Methods: A Comparison
| Method | Description | Best For |
|---|---|---|
| Polyurethane Foam Injection | Lightweight, expanding foam is injected beneath the slab to lift it gradually. Fast set time, minimal surface damage, and no water or mixing required on site. | Smaller to medium slabs, tight spaces, and jobs where speed and cleanliness are priorities. Ideal for residential driveways, patios, and walks in St. Louis neighborhoods. |
| Controlled Hydraulic Grout Injection | Precision-mixed grout is injected under pressure to fill voids and lift the slab. Allows real-time adjustment and is suited to large or heavily loaded surfaces. | Large commercial slabs, warehouse floors, and residential jobs where maximum precision and load-bearing capacity are required. Works well in areas with complex soil conditions. |
| Mud Jacking (Traditional Grout) | Heavier, water-based grout slurry is injected to fill voids and lift the slab. Slower set time and requires careful management to avoid over-lifting. | Large slabs and situations where material cost is a primary concern. Less common in modern residential work, but still effective for durable, long-term results. |
| Helical Piers and Mechanical Lifting | Steel piers or mechanical jacks are installed beneath the slab to support and lift it. Used when injection alone cannot achieve the required lift or stability. | Severely settled slabs, foundation work, and cases where the underlying soil is too unstable or compressible for injection methods alone. |
Concrete Leveling and Slab Lifting Cost in St. Louis: What to Expect
Concrete leveling and slab lifting in St. Louis typically starts at $4 per square foot, though the final cost depends on several factors unique to your property and the local soil conditions. A typical 20-by-12-foot driveway slab, for example, might cost between $960 and $1,440 to level, depending on the depth of settlement, the number of injection points needed, and the method chosen. Larger patios, multiple sunken areas, or slabs with complex soil conditions beneath them may cost more. Polyurethane foam injection is often slightly less expensive than hydraulic grout, and jobs in accessible areas with stable soil cost less than those in tight spaces or on properties with difficult terrain or utilities nearby.
Several factors move the price up or down from that starting figure. Depth of settlement is the biggest driver: a slab that has sunk 1 inch requires fewer injection points and less material than one that has sunk 4 inches. Size of the slab matters too, because larger areas require more injection ports and more material. Access and site conditions play a role as well. A driveway in a single-family home in Chesterfield with easy equipment access costs less than a narrow rear patio in a Soulard rowhouse where we must hand-carry materials through a tight alley. If underground utilities such as gas lines, electrical conduit, or plumbing run beneath the slab, we must locate and work around them, which adds time and care. Soil conditions also affect cost: if the ground beneath the slab is very soft, compressible clay or old fill, we may need more material to achieve stable lift than we would in firmer soil.
The best way to understand the cost for your specific job is to request a free, no-obligation estimate. We'll visit your property, assess the slab, identify the cause of settlement, and provide a detailed quote based on the method we recommend and the scope of the work. Most estimates are ready within 24 hours. Call (314) 916-1279 or visit our pricing page for more details on how we calculate costs and what's included in your estimate.
What to Look for When Hiring a Concrete Contractor Near St. Louis
Hiring the right contractor for concrete leveling and slab lifting is critical because the work is technical, the results are permanent, and poor workmanship can leave you with an uneven slab, cracked concrete, or drainage problems that cost thousands to fix. When you're evaluating contractors near St. Louis, start by asking each one for proof of general liability insurance and workers compensation coverage. Liability insurance protects your property if something goes wrong during the work, and workers comp covers injuries to the crew. Request a certificate of insurance from every contractor before they start, and verify that the coverage is current and adequate. This is the single most important protection you have as a homeowner.
Get at least two or three written estimates from different contractors, and compare them carefully. A detailed estimate should include the method (foam or grout), the number of injection points, the square footage being lifted, and the total price. If one estimate is dramatically lower than the others, ask why. It may be because the contractor is using a cheaper material or is underestimating the scope of the work. Check references from previous customers, especially those who had similar jobs in your neighborhood or on your type of property. Ask the contractor if they handle permitting and utility marking, because in some cases the city requires a permit for concrete work, and hitting a gas line or electrical conduit can be dangerous and costly. If your property is in an HOA community, confirm that the contractor understands any architectural review or approval requirements. Finally, make sure the contractor is responsive, answers your questions clearly, and is willing to explain the work in detail. You should feel confident in their expertise and comfortable with their professionalism.
Ready to get started? Contact us today for a free estimate and a conversation about your concrete leveling needs.
Concrete Leveling & Slab Lifting in St. Louis: Pricing Guide
| Service | Price | Details |
|---|---|---|
| Polyurethane Foam Injection | Starting at $4/sq ft | Fast, lightweight lifting for residential slabs; price varies by depth of settlement and slab size |
| Hydraulic Grout Injection | Starting at $5/sq ft | Precision method for larger or heavily loaded slabs; cost reflects greater control and material volume |
| Multiple settled areas or complex soil | On estimate | Severe settlement, utilities beneath slab, or difficult access require on-site assessment and custom quote |
| Travel | Included | No separate mileage or call-out fee within St. Louis and surrounding county service areas |
| Free estimate | No obligation | Site visit, assessment, and written quote delivered within 24 hours; call (314) 916-1279 |
Indicative pricing, the exact cost depends on square footage, finish, and site access. Free personalized estimate within 24h at (314) 916-1279.
