Many homeowners spot uneven sidewalks or driveway slabs and assume it’s just a minor eyesore. But sunken concrete often signals more serious issues below the surface, such as soil erosion or shifting ground under your home.
At Windler Foundation Repair, we’ve worked with many homeowners who waited too long to act and ended up facing bigger, more expensive problems. In this post, we’ll walk you through what causes concrete to sink, what signs you shouldn’t ignore, and how we typically fix the issue.
What Causes Concrete to Sink?
Soil Movement and Compaction Problems
Concrete needs a stable base to stay level. If the soil underneath is loose, not properly compacted, or made up of expansive clay, it will move over time. As moisture enters and exits the soil, especially with Kansas City’s freeze-thaw cycles, it can cause the soil to shift, leaving your slab unsupported.
Water Drainage Issues
Water plays a major role in undermining concrete slabs. Poor drainage around your home, leaking downspouts, or sprinkler runoff can wash away the subsoil under your driveway, patio, or walkway. Once the soil erodes or compacts, the slab above it starts to drop or tilt.
Signs You Shouldn’t Ignore Sunken Concrete
We often get called after someone has tripped on an uneven walkway or when a homeowner realizes water is pooling where it shouldn’t. But there are earlier signs that can save you trouble if you catch them in time.
Cracks Forming at the Surface
Cracks in concrete don’t always mean structural trouble, but when they show up alongside uneven settling, it’s a red flag. These cracks can widen over time, letting in more water and worsening the situation.
Water Pooling in New Areas
If you notice puddles forming on your driveway or patio that weren’t there before, chances are the slope of the slab has changed. This affects water flow and can eventually lead to water seeping into your foundation or basement.
Door Frames or Garage Entry Issues
Sometimes sunken concrete causes problems where slabs meet the foundation, such as at garage entries or steps leading into the home. If the concrete drops too far, it can interfere with how doors open or allow gaps for pests and water.
The Hidden Costs of Waiting
Trip Hazards and Liability
Uneven walkways are one of the most common reasons people trip and fall around a home. If someone gets injured due to a known hazard on your property, you could be held liable. Fixing sunken concrete now is far cheaper than dealing with an injury claim later.
Water Damage and Foundation Issues
Letting water pool around the base of your home puts pressure on the foundation. Over time, that water can seep into the concrete, create cracks, and even cause foundation walls to shift. What started as a sidewalk issue can easily become a foundation repair job if ignored too long.
Lower Curb Appeal and Home Value
We’ve worked with homeowners preparing to sell who were surprised by how much appraisers and inspectors note uneven concrete. It gives the impression of neglect and may raise questions about overall maintenance, even if the issue is isolated.
How We Fix Sunken Concrete
Our Go-To: Polyjacking
Polyjacking is a reliable, clean solution for lifting concrete back to where it belongs. We drill small holes through the slab and inject a high-density polyurethane foam underneath. That foam expands, fills voids, and raises the slab evenly.
The process is fast, most jobs are completed in just a few hours, and homeowners can walk or drive on the surface the same day. Compared to tearing out and replacing concrete, polyjacking is less invasive and more cost-effective.
When Replacement Might Be Necessary
In some cases, the concrete may be too damaged or cracked to lift effectively. If that happens, we’ll let you know right away and explain the replacement options. However, in most situations, polyjacking is the more practical and cost-effective solution.
When to Call a Professional
If you notice uneven slabs, new cracks, or water pooling, don’t wait. The longer the sunken concrete sits, the worse the damage gets and the more expensive it becomes to fix. At Windler, we start with a free inspection so you know exactly what’s happening beneath your slab.
We’re here to help you get ahead of the issue before it turns into a bigger repair. Our team will explain your options clearly and recommend the most effective, budget-conscious solution for your home.
Final Thoughts
Sunken concrete often indicates a problem below the surface. If left alone, it may lead to safety hazards, drainage issues, and damage to your foundation. The good news is that timely repair can prevent bigger problems.
Contact us at Windler Foundation Repair today to schedule a free, no-pressure evaluation and see whether polyjacking is the right solution for your home.
