09/03/2026
Most people assume concrete sinks because the concrete itself failed.
It didn't.
In almost every case, the slab is fine. What failed is the ground underneath it.
Here's what actually happens.
When a concrete slab is poured, it rests on a prepared base of compacted soil. Over time, that soil can shift.
- Water from rain or irrigation erodes it
- Dry spells cause it to contract
- Tree roots move through it
The soil that was supporting the slab starts to lose density, and small voids begin to form underneath.
The slab, which can't flex, starts to follow gravity. It settles toward the void.
That's the drop you see at the joint, the tilt toward the house, the uneven edge at the pool deck.
The concrete didn't break. The ground moved.
This is why surface patching doesn't solve the problem. Filling a crack from the top doesn't address the void underneath.
The slab keeps settling because the root cause is still there.
Geo-polymer injection fixes the actual problem.
The polymer is injected through small holes in the slab. It flows into the void, expands to fill it completely, and stabilizes the ground beneath.
The slab is lifted back to level. And because the void is now filled with a lightweight, waterproof material, the settling stops.
The concrete you've been looking at isn't broken.
The ground beneath it just needs to be addressed.
Free estimate.
SlabjackGeotechnical.com
