Polyurethane grouting involves the injection of expanding polyurethane to fill and seal cracks and voids and re-level slabs.

Common uses
Create barriers to water flow
Fill voids
Re-level slabs
Seal cracks and joints
Process
The polyurethane grout is injected under low pressure through or adjacent to a slab of foundation. The grout then expands to fill the crack or void.
Polyurethane grouts can be single or multi-component, and can require a reactant or react when encountering water.
Advantages
Available with variations in viscosity, reaction time, reaction with water, expansion characteristic and flexibility of the reacted grout