Find your expert.
Fix your problem.
It only takes a few seconds.
Concrete slab sinking and cracking happens when the soil below the slab can no longer support the weight of it. The causes movement, and sinking and cracking can occur. Concrete that is cracked or out of level won't fix itself, and over time the additional damages become more serious and costly.
How did this happen?
Changes in soil moisture
Concrete is most often poured directly onto soil. It hardens and seems strong and permanent. However, the soil under the concrete can move over time due to changes in moisture. Different types of soils, especially clay, hold on to water and expands. When dry conditions occur, the soil contracts. This expanding and contracting creates empty spaces into which your concrete sidewalks, slabs, steps and patios settle, causing cracks.
Wash-out of soil
As water moves beneath your concrete slab, stairs, sidewalks or patio, it can wash away the soil that's supporting the weight of the concrete. This can be caused by plumbing leaks, erosion, heavy rains and many other reasons. Over time, with nothing left to support the concrete, it will begin to sink or cave in.
Poorly compacted fill soil
During the construction of a home, driveway, patio or sidewalk, soil is commonly moved around or spread out to get to the desired grade level. Often, the concrete slab is poured right on top of these fill soils that have been moved around. If the fill was poorly compacted, the fill soil compresses and settles, creating a void under the concrete. With nothing to support it, the concrete cracks, breaks and settles into the void.