If you live in the Chicago area, you’ve probably seen it:
Uneven sidewalks, sunken front steps, or driveway slabs that have dipped toward the garage. Sinking concrete is extremely common in our climate – but it’s not just “old age” or bad luck.
Most of the time, concrete sinks because the soil underneath it moves, washes out, or gets weaker over time. And in Chicagoland, one simple drainage mistake accelerates that process more than anything else.
In this article, we’ll break down:
- Why concrete slabs around your home sink and crack
- How Chicago’s weather and soils make the problem worse
- The #1 drainage mistake homeowners make
- How Perma-Seal can help lift and stabilize sunken concrete
Why Concrete Slabs Sink in the First Place
Concrete itself is heavy and rigid. It doesn’t “bend” or flex very well. Instead, it relies on the soil underneath to support its weight. When that soil changes, the slab follows.
The most common causes of sinking concrete in the Chicago area include:
1. Soil Washout and Erosion
Water is the biggest enemy of the soil beneath your slabs.
When water repeatedly flows alongside or under your:
- Sidewalk
- Driveway
- Patio
- Garage floor
- Pool deck
…it can slowly wash away the supporting soil, leaving voids or soft spots underneath. With nothing to hold it up, the concrete begins to sink, tilt, or crack.
This is especially common near:
- Downspouts that discharge too close to the slab
- Low spots where water naturally pools
- Driveways with poor drainage toward the street
2. Poor Compaction During Construction
When your home was built, the soil around the foundation and under concrete slabs should have been properly compacted. If fill dirt was placed quickly and not packed down in thin layers, it can compress over time under the weight of the concrete.
That ongoing compression leads to settlement and sinking slabs years after the home was built.
3. Chicago’s Freeze–Thaw Cycles
In Chicagoland, we deal with frequent freeze–thaw cycles in fall, winter, and early spring.
Here’s what happens:
- Water enters small gaps and pores in the soil.
- When temperatures drop below freezing, the water expands as it turns to ice.
- The soil and concrete move slightly as that ice expands and contracts.
- Over time, this movement weakens the support beneath the slab.
Combine that with erosion and poor drainage and you get the perfect recipe for sunken, uneven concrete.
The #1 Drainage Mistake Homeowners Make
So what’s the biggest mistake we see when it comes to sinking concrete and settling slabs?
Downspouts that dump water right next to the concrete and the foundation.
It doesn’t look like much, but over time, this one issue can:
- Saturate the soil around your foundation and slabs
- Wash out soil beneath steps, walks, and driveways
- Increase hydrostatic pressure against foundation walls
- Lead to both sinking concrete and foundation problems
How Problem Downspouts Damage Concrete
When your gutters and downspouts are not set up correctly:
- Short downspouts or missing extensions drop water right at the base of your home.
- Buried downspout lines that are clogged or broken leak water into the soil.
- Gutters that overflow send sheets of water straight onto your driveway, sidewalk, or patio.
Instead of carrying roof runoff safely away, all that water concentrates in the worst possible locations – directly under or beside your concrete and foundation.
Over months and years, that leads to:
- Soft, unstable soil
- Erosion and voids under slabs
- Settlement and cracking
- Trip hazards and drainage problems
The good news? Fixing downspout drainage is often one of the easiest and most cost-effective ways to slow down future sinking once your slabs have been repaired.
Warning Signs Your Concrete Is Sinking
If you’re wondering whether your concrete is just a cosmetic issue or something to take seriously, look for these signs:
- Uneven sidewalks where one panel sits higher or lower than the next
- Sunken front steps pulling away from the porch or stoop
- A driveway slab that tilts toward the garage, trapping water
- Gaps under slabs where you can see exposed edges or soil washed out
- Water pooling on concrete instead of running off
- Cracks that coincide with low or sunken areas
These are not just eyesores. They can be trip hazards, worsen drainage around your home, and, if near the foundation, potentially contribute to water intrusion issues in the basement.
Why Replacing Concrete Isn’t Always the Best Move
When homeowners see sinking concrete, they often assume the only solution is tear-out and replacement. While there are times replacement makes sense, it often:
- Costs more than lifting in many situations
- Does nothing to address the soil problems that caused the sinking
- Takes longer to cure and be usable again
- Can damage adjacent landscaping or hardscapes
If the concrete is structurally sound but has settled or become uneven, there is often a better option.
How Perma-Seal Lifts and Stabilizes Sinking Concrete
Perma-Seal offers modern concrete lifting and leveling solutions that are designed specifically for issues caused by soil washout and poor drainage.
Instead of tearing out and replacing the slab, we:
- Drill small, strategic injection ports in the affected slab.
- Inject high-density polyurethane foam beneath the concrete.
- The foam expands, fills voids, and gently lifts the slab back toward its original position.
- Once cured, the foam stabilizes the soil and supports the slab long term.
Benefits of Polyurethane Concrete Lifting
- Fast turnaround – Most projects are completed in hours, not days.
- Minimal disruption – Small injection holes and no heavy demolition.
- Stabilized subgrade – Voids are filled and problem soils are supported.
- Traffic-ready quickly – Many surfaces can be walked or driven on the same day.
This approach directly tackles the effects of soil washout and erosion, rather than just covering them up.
Pairing Concrete Repair with Better Drainage
To protect your investment and help prevent future sinking, it’s smart to address drainage at the same time you fix your concrete.
Perma-Seal can evaluate:
- Where your downspouts discharge
- How water moves across driveways, walks, and patios
- Whether grading or small drainage changes could help move water away
By combining concrete lifting with better water management, you greatly reduce the risk of repeat settlement and protect both your slabs and foundation.
Is Your Concrete Sinking Around Your Chicago-Area Home?
If you’ve noticed uneven sidewalks, sunken steps, or a driveway that no longer drains the way it should, it’s time to take a closer look. In the Chicago area, sinking concrete is usually a sign that water and soil movement are already at work around your home.
You don’t have to guess what’s going on beneath the surface.
Schedule a concrete inspection with Perma-Seal. Our team will evaluate your sinking slabs, identify possible drainage issues, and recommend a permanent repair plan tailored to Chicago’s climate and soil conditions.
Stop letting water win. With the right concrete leveling and drainage solutions, you can restore safety, improve curb appeal, and protect your home for years to come.
