Sunken Driveways: Repair or Replace?

Originally posted 9/28/18, revised 12/3/20

Once upon a time, when your driveway was freshly poured, it was a smooth, even surface without a crack in sight.  As the years have passed, that has changed.  Your drive has endured changing seasons, extreme temperatures, erosion, and of course- the wear and tear of vehicles.

All of these variables have an impact on your property as a whole, and the driveway shows the damage.  You may be thinking about replacing your driveway, which is an expensive and messy project that can disrupt your whole neighborhood.  But what if it’s possible to avoid that situation?

Acculevel has been repairing concrete slabs since 1996.  We’re a family-owned and operated company, serving Indiana and parts of the surrounding states. We’ve repaired driveways, garage floors, patios, and other concrete slabs for thousands of homeowners throughout our service area.  We want to give you the details about concrete lifting you need, to make the best decision for your driveway and property.

In this article, we’re going to explore the common causes of a sinking driveway, explain how concrete leveling works, and compare the costs of leveling versus replacement.

These photos were taken by Acculevel employees.  On the left is 2 sections of driveway before slabjacking, the right is the same sections after repair.

What Causes a Driveway to Sink?

Nature is to blame for most of the problems we have with concrete slabs.  Rain and seasonal variations do a lot of damage.

Erosion

During heavy thunderstorms, rain can have an immediate negative impact on your driveway.  The water can ‘wash out’ the soil under the drive, especially if your gutter downspouts are emptying near the driveway.  At Acculevel, we recommend that homeowners position downspouts a minimum of 10 feet from your home.

If your downspouts are not draining 10+ feet from your home, or if they are located next to the drive, consider downspout extensions. If you are a DIY-minded individual, extensions are something that you may want to do yourself; this link takes you to an article explaining why downspout extensions are important and gives you a tutorial to watch.

Issues with the Soil

Erosion can cause the concrete slab to settle, but sometimes human error plays a part.  If the soil is not properly compacted, or if the soil isn’t level and well-graded, the ground will erode faster. And sometimes, everything is done perfectly but the soil composition is soft; this can allow the soil to compress and the slab to sink.

Temperature fluctuations also play a part; winters in the midwest are known for their unpredictability.   As the ground freezes and thaws, gaps can form under the slab.

Frost Heaves

We just mentioned the freeze-and-thaw cycle that we experience in the winter.  This creates the ideal conditions for “frost heaves.”  We know that when water freezes, it expands, right?  This means soil that is fully saturated with water can also freeze.  And when it does freeze, it expands, pushing (heaving up) anything over/around it.

These issues explain why cracks form in your driveway.  When erosion causes one side of the slab to sink, or frost heaves push one side up, the pressure causes the concrete to crack.

How Does Concrete Leveling Work?

If you’re going to lift a concrete slab, you need to reach under it and install something to physically raise and hold it up.  It’s kind of like changing a tire on your car: you install a jack underneath the vehicle and leverage it, to hold the car where you need it. To accomplish this with your driveway, we drill holes through the slab and inject a material under it.

When Acculevel started a few decades ago, we did mudjacking.  Mudjacking is a type of slabjacking that is used when you’re injecting a specific material.  Although this material is called mud, it’s actually a type of grout: a mix of limestone, concrete, sand, and water.  As it solidifies and cures, it raises the slab.

But Acculevel is always exploring new repair methods, looking for the best possible options for our customers.  In 2015, after research, testing, and comparison, we adopted a new lifting material: a type of polyurethane foam.  The same slabjacking process is used: drill holes through the concrete and inject a lifting agent; only the material we inject is different.  As soon as the foam is released, a chemical reaction begins.  This makes the foam expand and harden, creating immediate lift.

Because the foam sets up so much faster than the traditional “mud,” we have better and more accurate control over the leveling process.  We have continued to track and test this material and the results since 2015; in our experience, slabjacking with the foam provides a more reliable repair that lasts significantly longer than mudjacking.

Want to see it in action?  This is a time-lapse video of our process:

We also have rough footage of the process, with a rarely-seen side view:

How Does Concrete Lifting Compare to Pouring New Concrete?

When we slabjack a driveway and fill the cracks, we restore the drive to a smooth and even driving surface.  But it can’t be “like new” because it’s still your original concrete.  Aesthetically speaking, new concrete is more attractive.

But having a new driveway poured is a slow, noisy, messy process.  The old driveway has to be demolished with a jack hammer, the concrete pieces are hauled away, and a new form for the driveway is built.  Then the concrete is poured, and has to cure.  All the while, you’re parking on the street.  Depending on where you live, this could be a frustrating task that negatively impacts your neighbors as well.

Slabjacking causes minimal mess and disruption, and sets up within minutes.  You should be able to park on your driveway within a few hours- no parallel parking required!  And- we know how important this is- having a new driveway poured costs at least twice as much as slabjacking.

Are You Ready for An Estimate?

What happens next is up to you!

If the answer is yes, make sure you find an experienced specialty company that provides the service you prefer, and make an appointment.  Please protect yourself, and verify the company is reputable, insured, and accredited by the Better Business Bureau.

If you live in Indiana or the surrounding states, contact us at Acculevel.  We will send one of our experienced project managers to meet with you, evaluate your drive, and recommend the best course of action for you.  We provide free estimates, and have a 4.9 (out of 5) rating with the BBB.

If the answer is no, and you want more information, we have additional resources to offer!

Want to know more about the differences between mudjacking and slabjacking? This article provides a side by side comparison of the two methods.

There are some instances where slabjacking is not a good fit.  We’ve put together an illustrated guide that explains when slabjacking will not work, and why.

Worried about someone coming to your home during the pandemic?  There are alternative ways to work with a contractor.

Not sure what to ask contractors?  We have a free downloadable guide of questions to ask a contractor, available to any homeowner for use with any type of contractor.