Expanding Polyurethane Resin:

Expanding Polyurethane Resin involves injecting a specially formulated resin into small holes drilled in the concrete. The resin expands and fills voids under the concrete, which raises it back to its original level. The resin hardens within minutes and is much lighter than cement grout, which reduces the stress on the concrete. It is a less invasive and much less messy process than cement grout. The resin provides a permanent solution to concrete settling and is more durable than cement grout.

Cement Grout:

Cement Grout involves pumping a mixture of sand, cement, and water under the concrete. The mixture fills the voids and raises the concrete back to its original level. It is a messier process as the mud needs to be cleaned up after the job is done. The process is more invasive and requires larger holes to be drilled into the concrete. Cement grout is a temporary solution and requires regular maintenance. The mixture can settle over time and need to be redone.

Conclusion:

In conclusion, both expanding resin and cement grout are effective in leveling concrete surfaces, but expanding polyfoam is a more durable and permanent solution, while cement grout is a messier and more temporary option.