Concrete settlement is the downward movement of a slab that occurs when the soil beneath it compresses, erodes, or loses volume, causing the concrete to sink below its original level.
In depth
Settlement is the general term for concrete sinking. It stems from a handful of common causes: soil erosion from water washing out the base, improper soil compaction during construction, expansive clay soils that shrink and swell, tree roots displacing soil, and voids left by water or sewer line breaks. Northern Illinois is especially prone to it because of extreme seasonal swings in moisture and temperature.
Left unaddressed, settlement produces uneven surfaces, trip hazards, cracking, and drainage problems. Polyurethane raising reverses it by filling the void and lifting the slab while stabilizing the soil that failed.
How Acme applies it. Acme attributes most settlement it sees to soil erosion, poor compaction, expansive soils, and tree roots, and notes the Northwest Chicago suburbs’ extreme environmental cycles as a driving factor.
Related terms: Differential Settlement, Subgrade, Soil Washout, Sunken Concrete, Frost Heave
Frequently asked questions
What causes concrete to settle?
Soil erosion, poor compaction, expansive clay soils, tree-root movement, and voids from water or sewer leaks are the leading causes, often accelerated by freeze-thaw cycles.
Can settled concrete be raised back to level?
Yes. Injecting polyurethane fills the void beneath the slab and lifts it back into position while strengthening the soil, so it is far cheaper than replacement.