# How Concrete Slab Lifting Works | Wichita Foundation > Drilling, injecting, filling voids, curing. See step by step how concrete leveling lifts a sunken slab back to grade and what to expect on-site. URL: https://www.wichitafoundationsolutions.com/guide/how-concrete-slab-lifting-works/ Last-Modified: 2026-07-03 You know how frustrating a sinking driveway or uneven patio can get, especially after a heavy Kansas rainstorm. We see this exact settlement issue daily as the team at Wichita Foundation Solutions. Homeowners often ask us, how does concrete leveling work, and is it a massive construction project? The short answer is no. Slab lifting is a highly precise, controlled process that permanently stabilizes your concrete without the mess of a full tear-out. Let’s look at the exact steps our technicians take on-site and explore how to handle the lifting process from start to finish. ## Step 1: Estimate and marking The estimate and marking phase determines exactly where to inject the lifting material based on a calculated grid pattern. A specialist maps out your slab to ensure the entire footprint rises evenly. Our process starts with checking the concrete for structural integrity and measuring the exact degree of settlement. Grid spacing usually ranges from 3 to 5 feet apart, depending on whether the target is a standard residential driveway or a thicker garage apron. This exact spacing is a crucial factor. Wrong patterns result in uneven lifts, while the right engineering ensures a clean, level surface. ## Step 2: Port drilling Port drilling involves creating small access points through the concrete directly into the void below. This step provides the necessary pathway for injecting the leveling material. Our technicians use a rotary hammer to drill through the slab carefully. For a polyurethane foam process, the required holes measure between 3/8 and 5/8 of an inch. These small holes contrast sharply with the traditional mudjacking process, which requires larger access points ranging from 1 to 2 inches in diameter. | Lifting Method | Typical Hole Size | Visual Comparison | | --- | --- | --- | | Polyurethane Foam | 3/8” to 5/8” | Size of a dime | | Mudjacking Slurry | 1” to 2” | Size of a quarter to a golf ball | Workers drill these ports straight through the concrete until they hit the empty space. That opening provides the direct access needed to inject the lifting compound. ## Step 3: Injection and lift The injection and lift step forces material under the slab to fill the void and push the concrete back to its original grade. This is the main event of the slab lifting process. For polyurethane foam, a two-part liquid resin pumps through the ports and immediately reacts, reaching 15 to 35 times its original volume. As it expands, the foam packs the soil tightly and lifts the heavy concrete slab perfectly back into place. The operator watches the lift in real time and stops the flow the moment the surface reaches grade. For mudjacking, a heavy sand-and-cement slurry pumps directly through the larger ports to push the slab upward. Both approaches lift the slab entirely from underneath, preserving the existing surface finish completely. ![Patched injection holes in a leveled driveway](/images/misc/small-patched-injection-holes-in-a-leveled-concret.webp) ## Step 4: Void filling continues after lift Void filling continues briefly after the lift to stabilize the entire footprint of the slab. This final injection ensures the concrete will not settle again. Once the slab reaches the proper grade, our operators pump a small amount of extra material to pack any remaining empty pockets in the soil. Polyurethane foam weighs only 2 to 4 pounds per cubic foot, stabilizing the underlying Kansas clay without adding massive weight. > **Fact:** A concrete slab supported securely across its entire base stays where you put it, while a partial void almost guarantees future sinking or cracking. ## Step 5: Patching Patching seals the drilled injection ports with a durable cement or grout mix. The goal is to make the access holes structurally sound and as visually discreet as possible. Our team cleans the ports thoroughly before filling them with a color-matched compound. The final appearance depends entirely on the method used: - **Polyurethane Foam:** Leaves a dime-sized patch that becomes virtually unnoticeable after a few weeks of weathering. - **Mudjacking Slurry:** Requires a 1 to 2-inch patch that remains slightly more visible, though it still blends quite well over time. ## Step 6: Curing and use Curing and use guidelines dictate when you can safely walk or drive on the leveled concrete. Usability returns very quickly compared to pouring a brand-new slab. Our polyurethane foam hardens in roughly 15 minutes. You can walk on the surface immediately and park a standard passenger vehicle on the driveway within an hour. Mudjacking slurry requires a significantly longer curing window, often taking 24 to 72 hours before safely handling heavy vehicles. Both materials need a day or two to reach full design strength, but everyday usability happens remarkably fast. > **Quick Tip:** While foot traffic is usually fine within hours for both methods, keep heavy equipment like moving trucks or RVs off a mudjacked slab for at least three full days. ## What to expect on-site Knowing what to expect on-site helps you plan your day around the concrete leveling process. Most residential repairs wrap up in a single afternoon with minimal disruption. Here is a quick breakdown of a typical project: - **Crew size:** usually 2-3 trained technicians on a standard residential job. - **Time on-site:** 2 to 6 hours for most properties, depending on the number of voids. - **Noise level:** moderate. You will hear a rotary hammer drilling the ports and a compressor running the injection pump. - **Mess level:** exceptionally low. We sweep and wash the surface thoroughly before we leave. - **Access needs:** room for the pump truck within hose reach of the slab, which often extends up to 200 feet for tricky backyard patios. ## Which method to choose Choosing between methods depends entirely on your specific property needs, budget, and long-term goals. Both polyjacking and mudjacking successfully lift concrete, but they perform differently over time. Our polyurethane foam is completely waterproof, making it highly resistant to erosion if your yard suffers from poor drainage. The mudjacking process is generally more budget-friendly upfront, but the heavy sand-based slurry can wash out if heavy rains consistently run under the slab. | Feature | Polyurethane Foam | Mudjacking Slurry | | --- | --- | --- | | Material Weight | 2 to 4 lbs per cubic foot | Up to 100 lbs per cubic foot | | Water Resistance | Highly waterproof | Can erode or wash out | The final decision comes down to weighing the upfront cost, required cure time, drill hole size, and longevity. Read our mudjacking vs polyjacking guide [/guide/mudjacking-vs-polyjacking/ →](/guide/mudjacking-vs-polyjacking/) to walk through the full comparison and make an informed decision. ![Level across two lifted slabs](/images/misc/level-shown-across-two-slabs-of-a-freshly-lifted-p.webp) ## When lifting will not work Concrete lifting will not work if the slab is structurally compromised beyond a simple settlement issue. Some sunken driveways require a full tear-out and replacement. We see many cases where tree roots have shattered the surface into dozens of small pieces. As of 2026, complete concrete replacement is a messy process that often costs thousands of dollars more than leveling, so the best approach is to avoid a tear-out unless the concrete is severely fractured. Because of the high cost, our technicians always try to save the slab if it remains structurally intact. Our leveling vs replacement guide [/guide/concrete-leveling-vs-slab-replacement/ →](/guide/concrete-leveling-vs-slab-replacement/) explains exactly where we draw the line. ## Free on-site estimate A free on-site estimate gives you a firm price and a clear plan to fix your specific settlement problem. The goal is always to provide the most cost-effective and permanent solution for your property. Bring us a sunken slab, and our technicians will take exact measurements to calculate the material required for your specific drop. Book your inspection today through our concrete leveling service [/concrete-leveling/ →](/concrete-leveling/) or call 316-264-6666 to get started on an even surface. COMMON QUESTIONS ## Questions about this topic How long does concrete leveling take? + Most residential slabs are lifted in a few hours and usable soon after. Larger jobs can take a full day. Curing time depends on the material. How big are the holes? + Small. Roughly coin-sized for polyurethane foam, roughly golf-ball-sized for mudjacking slurry. Both are patched before we leave. How soon can I use the surface? + Polyurethane foam typically supports vehicle traffic within an hour or two. Mudjacking slurry usually needs to cure overnight. We tell you specifics on-site. ## Have a specific question about your home? Our specialists give honest, no-pressure reads on foundation, drainage, and basement problems across south-central Kansas. Free On-Site Estimate [/contact/ →](/contact/) OR CALL DIRECTLY 316-264-6666 [tel:3162646666 →](tel:3162646666)