MY DRIVEWAY IS SINKING – DO I HAVE TO REPLACE IT?

A sunken driveway is not only an eyesore; it can become a hazard—potentially damaging vehicles, creating an unsafe walking surface, and lowering your property value. Many homeowners panic and think their only option when noticing uneven concrete in their driveways is to fully replace it. Before committing to that decision and expense, you should understand why driveways sink and learn about repair options, such as polyjacking, mudjacking, or polyurethane foam injection, that can effectively restore your driveway. These methods may preserve both the function and appearance of your driveway—while saving you money in the process.

PRIMARY CAUSES OF DRIVEWAY SINKING

Understanding why your driveway is sinking is the first step toward effective repair. Several factors can contribute to this common problem:

SOIL EROSION AND SETTLEMENT

Over time, the soil below your driveway compacts naturally. Heavy rain can wash away the soil particles that create voids under the surface. When these voids get bigger, the concrete or asphalt loses support and begins to sink. Not all soil types behave the same way when wet or pressured. Clay soils definitely have further complications due to their ability to expand and contract.

POOR INITIAL INSTALLATION

A good site preparation for a lasting driveway involves adequate compaction of the soil and a stable base. If contractors use subpar materials, don’t compact things correctly, or mix the concrete wrong, the driveway sinks as it ages. A lot of homeowners do not realize that what they are experiencing is due to corners cut during the original installation years earlier. PolyMagic is a leading foundation grading and drainage team. 

WATER DRAINAGE ISSUES

Poor drainage is probably the most common culprit for settling driveways. Water runoff that pools around your driveway washes out the soil base, especially in sloped neighborhoods like those in Lee’s Summit or Lake of the Ozarks. When water constantly pools around or beneath your driveway, it disrupts the soil foundation. Off-target downspouts, sloped lots that channel water toward the driveway, and inadequate perimeter drainage all cause erosion and soil destabilization. Correcting these situations is often critical to preventing further damage.

FREEZE-THAW CYCLES IN COLDER CLIMATES

In the Midwest—including the Kansas City Metro—we experience frequent freeze-thaw cycles each winter. Water seeps into small cracks in your driveway, freezes, expands, and gradually forces the cracks wider. This repeated process weakens the concrete, undermines its foundation, and displaces the ground beneath—eventually leading to uneven, unstable slabs.

TREE ROOT INTRUSION

Large trees on your driveway cause problems in two different ways. One, their spreading root systems literally cause sections of concrete or asphalt to rise up. Two, and less obviously, roots extract a tremendous amount of water from the ground, drying it out and leaving holes. With seasons changing, this process of hydrating and drying produces continuous motion under your driveway.

REPAIR OPTIONS FOR SINKING DRIVEWAYS

After learning why your driveway is sinking, you can undertake some of several types of repair options. What’s best will depend on how large the area of concern is, how much money you want to spend, and the quality of the entire driveway.

POLYJACKING

Polyjacking is a method by which high-density polyurethane foam is injected beneath concrete slabs to lift and level the slabs. The method begins with a small 5/8-inch hole drilled completely through the concrete at selected locations. The two-part polyurethane sealant is then pressed beneath the slab, where it quickly fills spaces beneath the concrete while lifting (typically within the duration of 15-30 seconds).

The advantages of polyjacking are less disturbance to the surrounding terrain, quick cure time (the driveway can usually be reopened in 15 minutes once it is complete), and more life than mudjacking. Polyurethane foam is light (it is approximately 2 pounds per cubic foot) but very strong, carrying heavy loads without adding much weight to possibly loose ground. It is also water-resistant and will not break down over time, making it ideal for water-damaged spaces. While more expensive than traditional mudjacking, its durability and overall quality often pay for themselves in the long term.

MUDJACKING/SLABJACKING

Mudjacking is the process of injecting a mixture of cement and soil underneath a sunk concrete slab to raise it back to its original position. With this technique, you drill holes in the concrete, inject the mixture, and seal the holes. It is cost-effective to replace and can usually be done in one day, so it is popular for driveways that are settling moderately.

POLYURETHANE FOAM INJECTION

A newer alternative to traditional mudjacking, polyurethane foam injection uses a light but stronger-than-concrete-slurry expanding foam. It requires smaller injection holes and is neater. Though typically more expensive than mudjacking, it has better long-term performance, especially in areas with unstable soil, because the foam will not wash away or compact over time.

PREVENTATIVE MEASURES

While fixing a sinking driveway is helpful, preventative measures can ensure this issue does not happen again.

PROPER DRAINAGE SOLUTIONS

Proper drainage is very important for driveway longevity. Moisture damage to driveways can be diminished by installing French drains along the sides of your driveway, putting downspout extensions in the right place away from the pavement, and creating gentle slopes directing water away from your driveway and foundation. Most experts suggest dealing with drainage issues first before attempting repairs.

REGULAR MAINTENANCE PRACTICES

Your driveway will last much longer with simple maintenance routines. Filling small cracks quickly stops water from getting through. It also helps having regular cleaning that removes small rocks, dirt, and any chemicals. You should check your driveway at least once in each season to fix any problems. Most experts say to get the whole driveway checked out at least twice a year.

SEALING AND PROTECTIVE COATINGS

Using the right sealants will help stop moisture, oil, and UV rays from reaching the surface. Siloxane-based sealers are ideal for concrete driveways as they allow moisture vapor to escape while blocking water ingress. Sealcoat your asphalt driveway every 2-3 years with coal-tar or asphalt-based sealer. These coats minimize freeze-thaw damage and slow the aging process. A sinking driveway does not require complete replacement. If you can determine why this is happening and choose the proper method of repair, you can fix your driveway at a fraction of the cost of replacement. If you take care of it and maintain it regularly, it will last for years. If your driveway continually sinks, consider PolyMagic’s for reliable results with little disturbance to your property. Call us to schedule a free estimate.

IN SUMMARY

You don’t always need to replace a sinking driveway. If you understand the cause and act early, you can often restore it through polyjacking or foam injection—saving time, money, and disruption. Many homeowners in Kansas City Metro and Mid-Missouri are surprised to learn just how quick and effective these repairs can be.