Sub-Base Void Filling & Polyurethane Slab Elevation Proposal
Challenge
A property owner in Cedar Point reached out to MidAmerica Basement Systems after observing sunken concrete slabs creating dangerous trip hazards along their walkway and driveway entrance. Sub-surface soil erosion from rainwater runoff had washed away fine dirt particles, leaving empty pockets beneath the heavy slabs. Over time, the unsupported concrete tipped and dropped several inches below the adjacent surfaces. Wanting to avoid the extreme noise, high costs, and lawn damage associated with tearing out and re-pouring the concrete, the owner requested a non-invasive repair proposal.
Solution
To lift the slabs and permanently consolidate the sub-grade, our specialist engineered a targeted PolyLevel® injection solution. The strategy uses penny-sized drill ports to inject lightweight, high-density expanding polyurethane foam directly into the underlying voids. As the foam expands, it flows through loose soil, fills all hidden pockets, and exerts precise upward hydraulic pressure to lift the concrete flush with surrounding slabs. Once elevated, the injection holes are patched, and open control joints are filled with dynamic silicone sealant to keep future rain runoff from infiltrating the soil base.
