Void Filling & Subgrade Repair

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     When concrete around your home begins to sink, tilt, or separate, it becomes a safety concern and affects both drainage and curb appeal. Many homeowners assume replacement is the only option, but polyurethane concrete lifting offers a cleaner, faster, and longer-lasting solution. Using precise injection techniques, we lift and stabilize settling slabs without the mess or downtime of mudjacking or replacement. Our method strengthens the soil beneath your concrete while restoring a smooth, level surface that lasts.

Over time, soil erosion, freeze–thaw cycles, poor original compaction, and water movement can cause concrete to settle unevenly. Our polyurethane lifting system targets the underlying cause by stabilizing weak soils and filling hidden voids before gently raising the slab back into position. This structural-grade foam expands into every gap even filling horizontally, creating a uniform support layer that won’t wash out, break down, or add unnecessary weight like traditional mudjacking material.

     This service is ideal for driveways, sidewalks, garage floors, patios, pool decks, basement slabs, steps, and entry approaches. Because the foam is lightweight and waterproof, it helps prevent future settlement and performs exceptionally well in Wisconsin’s climate.

Some of the most common residential applications include:
• Driveways and approach slabs
• Sidewalks and walkways
• Garage and basement floors

     Homeowners often choose foam lifting over mudjacking because it provides a cleaner appearance, smaller injection holes, much longer service life and faster results. The waterproof foam expands with incredible lifting strength while adding virtually no weight to the soil. This helps ensure the repaired area stays level and stable for many years.

Key benefits include:
• Immediate return to use
• Minimal drilling and a clean finish
• Lightweight material that won’t contribute to future sinking
• Long-lasting, environmentally stable foam that resists moisture

     Our process begins with a detailed inspection of the slab and underlying soils. Small injection points are drilled through the concrete, and our expanding polyurethane is injected below the slab. As it expands, the foam fills empty voids, compresses weak soils, and gently lifts the slab back into place. After leveling is complete, the access points are sealed for a smooth finish. Most projects take only a few hours, allowing you to use your repaired surface the same day.

      As a professional concrete lifting and soil stabilization contractor, we understand how different soil types, climates, and environmental conditions affect concrete performance across various regions. Whether your project is local or out of state, our team brings the same level of precision, high-quality materials, and honest evaluations to every job. If a slab is too damaged to salvage, we’ll tell you. Our commitment is to long-term stability, engineered solutions, and doing the job right — wherever the work takes us. 

     A void is an empty space beneath concrete caused by soil loss, erosion, water movement, or decomposed organic material. Once the soil is no longer in contact with the underside of the slab, the concrete is essentially floating—leading to sudden settling or cracking.

     Voids usually form from the bottom up, not the top down. Water runoff, poor drainage, gutter discharge, rodent tunnels, and frost expansion all remove or shift soil beneath the slab without leaving visible surface signs until the slab finally drops.

     Yes. Injecting polyurethane foam removes the empty space that allows a slab to fall. Once the void is filled and pressure is redistributed properly, the slab regains stable, uniform support and is far less likely to settle again.

     Absolutely. Hollow-sounding slabs are at high risk of sudden settlement. Filling the void early reinforces the subgrade before damage occurs, preventing costly future repairs.

     Yes. Structural-grade polyurethane foam is designed to withstand significant compressive loads. It is used under driveways, garage slabs, commercial floors, industrial pads, and even roadway pavement sections.

     Foam injection works exceptionally well for:
• Water erosion voids near seawalls, patios, and pool decks
• Rodent or burrowing animal voids under steps and walkways
• Sinkholes caused by soil washout or collapsed organic material
• Subbase failures under garage slabs, sidewalks, and driveways

     Yes. One advantage of polyurethane is its ability to flow laterally into hard-to-reach areas. It expands outward into all open gaps, filling irregular spaces that traditional slurry materials often miss with mudjacking.

     It can, but only if lifting is needed. Some projects require only void filling to reestablish support, while others use void filling as the first step before lifting. We control foam expansion precisely to avoid unintended movement.

     Yes. Subgrade washout behind seawalls and retaining walls is one of the most common applications. Foam displaces water, fills subsurface cavities, and stabilizes soils to prevent further washout.

     Void filling with polyurethane is considered a long-term repair because the foam does not shrink, dissolve, absorb water, or decompose. It forms a permanent support structure underneath the slab, making it far more durable than sand, gravel, or mudjacking slurry.