The Problem:

The homeowner was dealing with settlement in six concrete driveway sections.

During an inspection of the property, Zavza Seal’s senior estimator and project manager found that the soil layers beneath the concrete slab had shifted. This movement created significant voids underneath the driveway.

When these empty spaces form beneath a concrete slab, the slab can lose some of its support. Over time, this can cause sections of the driveway to settle and become uneven.

In this case, the problem was not simply the concrete surface. The space underneath the driveway needed to be addressed.

The Solution:

Zavza Seal proposed using Poly-Jacking concrete lifting to fill the voids beneath the settled driveway sections and raise the concrete back toward its original position.

Poly-jacking uses a high-density polyurethane material that is injected beneath the concrete through small drilled holes. As the material expands, it fills empty spaces and can provide support beneath the slab.

Step 1: Identify the Lifting Points

The crew used diamond bits to drill 3/8-inch holes at carefully selected locations in the concrete.

The exact number and location of the holes were determined by the project manager based on the condition of the driveway and the best lifting points.

Step 2: Fill the Voids

A two-component, high-density, closed-cell polyurethane foam was injected through the drilled holes.

The foam was injected until the voids beneath the concrete were evenly filled.

This type of polyurethane foam is commonly used for concrete lifting applications where filling voids and providing support beneath slabs are important.

Step 3: Lift the Settled Concrete

As the polyurethane foam expanded beneath the driveway, it created upward pressure against the concrete.

The goal was to raise the settled driveway sections back toward their original elevations while filling the empty spaces underneath.

This approach addresses both parts of the problem: the void beneath the slab and the resulting settlement.

Mudjacking as an Alternative

Mudjacking was also considered as an alternative repair method.

With mudjacking, the crew would drill holes in the affected concrete and pump a stone slurry grout underneath the slab.

The grout would fill the voids beneath the concrete. As the material was pumped underneath the slab, the pressure would gradually lift the settled concrete toward its original height.

The final repair method depends on the conditions of the individual project and the recommendation made by the project manager.

Completing the Driveway Repair

After the lifting and void filling were completed, Zavza Seal would patch the holes drilled into the concrete.

The team would also seal the expansion joints in and around the affected driveway area.

Because the existing concrete has aged and weathered, the color of the patched areas may not perfectly match the surrounding slab.

The Result:

The repair was designed to address the underlying voids that contributed to the driveway settlement rather than simply treating the uneven concrete surface.

The project scope included:

• Repairing six settled concrete driveway flags
• Drilling small access holes using diamond bits
• Filling the voids beneath the concrete
• Using high-density closed-cell polyurethane foam for the proposed Poly-Jacking method
• Lifting the settled concrete toward its original position
• Patching the drilled holes
• Sealing expansion joints around the affected area

By filling the voids beneath the driveway, the repair provides support where the concrete had lost contact with the underlying soil layers.