Why is my concrete sinking?
Posted Mar 17, 2021 in Concrete Raising
What caused your concrete slab to sink? (The concrete we are referring to include sidewalks, driveways, patio slabs, pool decks, and even some home foundations.) Most concrete slabs are free-floating which means they rest on the soil beneath them. If you take away soil, your slab will move. It’s that simple. Family Waterproofing Solutions can raise, level and stabilize your sunken concrete; however, we feel it is important for you to understand what causes these issues. Here are the 2 major reasons why your concrete slab can sink:
Natural characteristics of soil
If you were to conduct a soil test around the Greater Chicagoland area and surrounding townships, you would be amazed by the varying compositions of our soils. These compositions will bear different load capacities, settle and compact differently, and expand/shrink in wet or dry climates. With the right soil composition and preparation, you will have very little problems with uneven, sunken concrete slabs. Here are a few things to remember:
- Soils will naturally compact and settle over time. Proper soil type and compaction are required to support concrete slabs. Many slabs require bringing in select fill soil as a base. The proper thickness/amount is often determined by a company that conducts a soil boring test.
- Soils that contain large amounts of clay will shrink and expand during dry/wet climates. This movement will cause your concrete slabs to become uneven over time. Proper drainage and irrigation can help control huge movements of your concrete slabs.
The soil underneath your sidewalk, driveway, patio slabs and other concrete surfaces offer support and stabilization. Water can wash away soil; furthermore, this will cause voids underneath your concrete slabs. Over time, your concrete will begin to sink or even crack due to the lack of support. Here are a few main reasons why this happens:
- Home gutters washing out the soil underneath driveways and sidewalks
- Natural drainage routes water underneath driveways and sidewalks (drainage between houses routed to the street will usually cross a sidewalk)
- Concrete expansion joints rotting away and not being replaced causes water to wash away soil
- Weed eaters causing deep canals around your driveways and sidewalks (easily fixed by adding soil or sand every year
Get a free concrete lifting estimate
Family Waterproofing Solutions can raise, level, and stabilize your concrete slabs for an affordable price. One of the biggest advantages of using polyurethane foam is that it fills the voids while also adding stability. On top of that, it’s waterproof. Call our team at (708) 330‑4466 for more information or to get a FREE estimate.
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