Garage Approach Concrete Stabilization
Challenge
A residential garage approach installation in Pekin, IL, suffered from severe localized slab settlement directly in front of the garage door entry, resulting in dangerous winter ice formation and persistent surface runoff pooling. System Design Specialist Tim Rollet conducted a diagnostic field evaluation and determined that the structural failure stemmed from hydraulic subgrade washout beneath the load-bearing concrete matrix. Unsealed control joints and expansion seams allowed snowmelt and rainwater to migrate beneath the slab-on-grade assembly, eroding fine-grained supporting subbase soils over time.
As subgrade material washed away, unsupported subterranean voids formed directly beneath the garage apron. Deprived of uniform, continuous base support, the concrete slabs sheared along control lines and settled below the threshold grade, reversing the designed drainage fall away from the home. The primary engineering challenge was to consolidate the degraded subgrade, fill hidden subterranean void pockets, and precisely lift the settled concrete back to a positive slope without applying heavy cementitious materials that could induce secondary consolidation in the weak subbase, and without conducting high-impact slab demolition.
Solution
To restore proper drainage fall and structural slab elevation without invasive replacement, System Design Specialist Tim Rollet engineered a two-stage geopolymer lifting and hydro-sealing protocol using PolyLevel® Concrete Leveling and NexusPro® Joint Sealant. Operations Lead Justin Maddox and field technician Devin S. executed the repair by drilling pea-sized (5/8-inch) injection ports through the settled concrete slabs at calculated load-bearing points.
Using specialized high-pressure injection equipment, the crew pumped a high-density, hydrophobic two-part polyurethane foam directly beneath the concrete matrix. As the two-part geopolymer expanded, it filled subterranean void spaces, compacted loose surrounding subbase soils under pressure, and generated upward hydraulic force to raise the settled concrete back to a flush, properly sloped elevation. Following precision lift management, the team cleared all open seams of debris and applied UV-resistant NexusPro silicone joint sealant along every crack and joint, establishing a highly flexible, water-tight barrier capable of accommodating seasonal thermal expansion and contraction cycles. The crew then sealed the injection ports with matching cementitious grout, completely eliminating pooling hazards and leaving behind a fully stabilized garage entrance ready for immediate vehicular load.
