Why Does Concrete Settle?
Concrete may settle due to poor drainage, low-quality compaction, damaged site conditions, tree roots, and many other reasons. The most common reason is when water from gutters or rainwater washes away dirt from under concrete sidewalks or driveways. It creates voids or pockets underneath the concrete, which causes it to settle.
Your concrete may also settle if there is clay-rich soil. The soil expands when it’s saturated with water. Then, when the soil dries, it contracts. Thus, the soil remains unstable with changing moisture levels, which causes concrete to move and sink.