Apartment Floor Leveling in Waterloo

The Challenge

Groundwater presence washed away soils underneath apartment complex floors.

Uneven floors aren’t just an inconvenience; they can signal problems beneath the surface. What looks like a slope in the flooring may mean the soil below has shifted or washed away, leaving voids that threaten the stability of structures above. At an apartment complex in Waterloo, Ontario, the slope the complex was built on and groundwater presence had washed away soil underneath 2 of the building’s slab on grade (SOG) floors. This soil loss led to voids, creating uneven floors and gaps under partition walls. For residents, this could create trip hazards, difficulty moving furniture, and potential issues with doors and windows no longer closing properly. For the property owner, it raised concerns about tenant safety, building code compliance, and long-term structural integrity if the voids were left untreated. Additionally, they needed a solution that would get tenants back into their apartments quickly.

Key Facts

The Solution

Polyurethane injection floor leveling.

The owner of the complex contacted Groundworks because the team could offer a minimally invasive, less disruptive, and cost-effective long-term solution. After a survey of the job site and formulation of a plan, the Groundworks employees began to work swiftly: they drilled holes in the SOG floor and injected high density polyurethane through the holes. The polyurethane moved into the soils beneath the slab in its liquid form and then expanded to fill voids and lift the concrete slab floor. The slab was carefully monitored throughout the process to ensure proper lift.

The Impact

Both building floors were lifted in a single day.

By directing injections near the most affected areas, including gaps beneath partition walls, crews ensured that the voids were stabilized without damaging interior finishes. Both building floors were lifted in a single day, minimizing downtime and allowing the General Contractor to reinstall floor coverings and repair drywall as needed. Finishing the injections in just one day kept the project on schedule and supported the top priority: getting tenants safely back into their homes as soon as possible. In addition to restoring immediate stability, the polyurethane injection provided a long-lasting solution that resists future soil washout and settlement, reducing the likelihood of repeat issues. The minimally invasive approach also helped the owner avoid the significant cost, mess, and extended disruption that would have come with full slab replacement.