Concrete does not have to be weak for a slab to move. If support below a panel changes because soil shrinks, softens, washes out, or was unevenly compacted, the rigid slab can settle into the unsupported space.
Polyurethane foam injection is a concrete-lifting method in which material is introduced beneath a suitable slab to help fill voids and raise the surface in a controlled way. A site review is needed to decide whether the slab is a candidate.
A sidewalk deserves attention when adjacent panels no longer meet evenly, walking paths feel unstable, or water and debris collect at the low edge. Prompt evaluation helps clarify whether leveling is feasible.
Repair can make sense when substantial sections remain sound and the main issue is settlement, isolated cracking, or failed joints. Replacement becomes more likely when deterioration is widespread or the slab cannot serve its intended load.
Homeowners often notice a rocking slab, a new lip between sections, or water collecting where it did not collect before. Those are reasons to investigate; they are not a diagnosis by themselves.
