Polyurethane concrete lifting uses a purpose-made two-component polymer system injected through small holes into voids or weak support zones beneath a slab. Expansion can fill space, re-establish contact and—when controlled—raise the slab. It is not the same material or use case as canned household insulating foam.
What Happens During a Typical Lift
- Small injection ports are drilled through the slab.
- Material is injected in controlled amounts beneath the concrete.
- The reacting polymer expands and fills available void space.
- Additional metered injections can apply upward force where lifting is appropriate.
- Elevation, joints, adjacent structures and slab response are watched continuously to avoid over-correction.
- Ports are patched after the work.
Void Fill, Soil Stabilization and Lifting Are Different Objectives
Marketing often compresses all three into “concrete lifting.” They are not identical. Filling a void restores contact; treating loose soil is intended to improve the support zone; lifting intentionally changes elevation. A proposal should say which problem is being addressed and how success will be measured.
Why Florida Homeowners See This Service Advertised
Florida contractors commonly market polyurethane injection for settled driveways, sidewalks, patios and pool decks. Helicon, for example, publishes Florida projects using separate soil and slab injections around pool decks. Those contractor case studies are useful demonstrations of the method, but they should not be treated as proof that every settled slab needs polyurethane or that every cause of settlement is the same.
Questions Worth Asking Before the Holes Are Drilled
- What evidence shows a void or support problem under this particular slab?
- Is the goal stabilization, elevation correction, or both?
- What fixed elevations limit how far the slab can safely move?
- What caused the support loss, and what prevents it from recurring?
- What happens if the slab cracks during lifting?
- How will repaired ports and existing cracks affect the coating or overlay planned afterward?