As snow melts and rainwater soaks into the soil it will swell and shrink. Over time, this will cause the concrete on top of that soil to shift and move around. As it moves, open spaces or voids are created below ground. The shifting concrete can eventually settle into these voids and eventually create gaps or cracks in slabs. Even thick concrete can become uneven and slope over time.
Why Is My Concrete Sinking?
There are a number of situations and factors that will contribute to sinking concrete. Some reasons could be drastic changes in the moisture content of the soil from weather or a plumbing leak, tree roots growing below the slab, animals digging around the concrete, or even an extended period of dry weather causing the soil to become depleted of moisture and contract. The causes we normally see are the following:
If there is hot or dry weather for extended periods of time, it will cause soil shrinkage. As the soil dries out, it will create voids under your concrete. Over time, these voids cause pressure and stress on the concrete slab that will eventually cause it to crack.
As the moisture level in your soil is fluctuating over time, it can cause the concrete sitting on top of that soil to become damaged. If the soil is saturated due to poor drainage, this moisture will cause the soil to become weak and no longer be able to support the concrete. Conversely, if there is too little moisture in the soil, it will contract and cause soil shrinkage.
When soil has been removed and replaced, it is necessary that it is compacted to the original density as when it was removed. If the soil is not properly compacted, it can speed up the creation of voids under any concrete poured above. These voids will put unnecessary stress on the slab and cause cracks over time.
Where does concrete need to be leveled?
Anywhere there is soil below your concrete, you could be in danger of needing concrete leveling. These are the main areas that we've seen both business and residential property owners needing our services:
Our Solutions: Mudjacking and Polyjacking
The use of mudjacking to repair sinking concrete is the industry standard. This process involves pumping a mixture of cement and fine aggregates into the cavity below the sunken concrete. Once this slurry hardens, it is the equivalent to creating a new footing for the concrete slab.
Polyjacking is a newer method of concrete raising. This is done with an expanding polyurethane foam that is pumped in similar to mudjacking except with a non-hazardous inorganic foam instead of the cement slurry.
How It Works
A pattern of holes are drilled into the sunken concrete slab. 1 5/8" for mudjacking and 5/8" for polyjacking.
The lifting medium is pumped under the slab. As the void is filled, the slab lifts up to its original position.
When completed, the holes are patched and we perform a complete clean up before we leave the site.
If you're in need of permanent concrete slab raising and leveling, contact us today for an estimate.