Why Concrete Sinks in Indiana

This is the dominant mechanism. Water moving beneath or alongside a slab carries fine material with it, and support is lost where the material used to be. The usual sources are unremarkable: a downspout discharging next to a driveway, grading that sends runoff along a slab edge, a joint that lets surface water down, or a buried line that leaks.

Because the mechanism is water, it is repeatable. Fix the slab and leave the water, and the process resumes.

A great deal of residential concrete sits on ground that was disturbed during construction: backfill placed against a foundation wall, spoil returned over a utility trench, or fill brought in to shape a lot. Where that material was not fully consolidated, it keeps settling for years afterward, and anything poured over it follows.

That is why aprons, garage floors and slabs immediately against the house are so often the first to move.

Soils change volume with moisture content, some more than others. Ground that dries and rehydrates through the seasons provides support that varies over time, and a slab bridging that variation gradually loses continuous contact. How pronounced this is on any given property depends on the actual soil there, which is a site-specific question we will not answer generically.

Central Indiana has a climate that freezes and thaws repeatedly through winter rather than staying frozen. Each cycle works saturated ground beneath and beside slabs, and water present in the concrete itself contributes to surface deterioration. This is a genuine contributing factor here; it is not, on its own, a sufficient explanation for a specific slab dropping.

Filling and lifting restores the slab. Whether it stays restored depends on whether the mechanism is still active — which is why the most useful question to ask a provider is not "which foam do you use" but "what do you think caused this, and what stops it continuing".

See how long concrete leveling lasts and water pooling on sunken concrete.