Why concrete sinks
Posted Mar 31, 2021 in Concrete Raising
Sinking concrete – you’ll come across it in the form of uneven, cracked, or sunken concrete slabs. And it doesn’t happen without cause. In fact, slab settlement is to blame when it comes to your uneven concrete slabs. What is slab settlement you ask? Well, slab settlement refers to the movement a concrete slab experiences when the soil below can no longer support the weight of it.
Sinking concrete problems and causes:
When it comes to slab settlement, soil changes underneath your concrete slab is the culprit. While there are many reasons why the soil may change underneath your concrete slab, there are three main causes.
- Soil Washout under the Concrete Slab
- Poorly Compacted Fill Soil
- Soil Moisture Content Changes
Soil washout under the concrete slab
Water caused by plumbing leaks, erosion, large rains, etc. will find its way underneath your concrete slab. As this water moves underneath your concrete slab, it can wash away the soil that’s supporting the weight of the concrete. As this process re-occurs over time, the amount of soil present underneath the concrete slab will diminish and your concrete slab will begin to sink because there is not enough soil to support the weight of the slab.
Poorly compacted fill soil
During the construction of a driveway, patio, sidewalk or home, the soil is most often spread out or moved around to achieve the desired grade level. If a new concrete slab is poured right on top of this loosely compacted soil then slab settlement is more likely to occur. As the fill soil underneath the slab compresses and settles, empty space is created under the concrete. So, with nothing to support it, the concrete breaks, cracks, and settles into the empty space.
Soil moisture content changes
Cycles of wet and dry have a direct effect on the soil underneath the concrete slab. When soil types like clay get wet, it holds onto the water and expands in size. When the soil becomes dry due to occurrences such as drought conditions or tree roots drawing valuable soil moisture, soil begins to shrink, creating empty space under the slab, resulting in uneven and cracked concrete.
Learn how we can level your concrete slab
Family Waterproofing Solutions has the expertise to evaluate your uneven, cracked concrete slabs, allowing you to quickly enjoy using those areas around your home. If you would like to learn more about concrete leveling services, contact us today for your no-obligation free estimate.
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