How Sinkholes Form

Sinkholes can form in a variety of ways. Here in Maryville, Tennessee, the most common way is often because of the limestone below the surface of our soil. Limestone is extremely porous, which makes it incredibly easy for water to eat away at it. As the limestone gets weaker, it can crack and give way to form a sinkhole. Sinkholes come in three main varieties. 

Sink hole

Solution sinkholes

This is an extremely common sinkhole that happens when very little surface soil covers the limestone below. It allows more water to come in, so the hole begins small and eventually gets bigger. These sinkholes are usually bowl-shaped and will collapse suddenly if they aren’t fixed immediately.

Sink hole in road

Cover collapse sinkholes

These sinkholes occur in areas where there is a lot of soil or sand above the limestone layer. The limestone deteriorates slowly because less water is able to get through the top area. As the limestone begins to fail as a support system, the weight of the area above cracks. This type of sinkhole occurs quickly rather than gradually. 

Sink hole in road

Cover subsidence sinkholes

This occurs when the topsoil is high in clay content. As the limestone layer begins to crack, the clay moves in to take its place. This type of sinkhole will leave a large depression, but because the clay has moved into place, there is still support, so the sinkhole is typically shallow.


When a sinkhole begins to form on your property, it is best to treat it quickly. Here at American Foundation & Waterproofing, our Maryville sinkhole repair contractors know a thing or two about how to best repair any sinkholes in the area. Our experts will come out and assess the sinkhole to determine the best sinkhole repair solution. We use three main techniques: compaction grouting, cap grouting, and injection piers. 

Compaction grouting is done by injecting cement grout in a grid pattern to restabilize the soil particles, allowing the remaining soil to push together. Cap grouting is similar to compaction grouting, but instead of a grid pattern, we “cap” the void that the hole left so that the soil can’t sink any further. Injection piers are utilized by drilling a hole and injecting grout mixture into the hole, which will reach all the perforated holes and escape into the soil to create a solid foundation. Our Maryville sinkhole repair service experts will be able to assess the type of sinkhole repair solution that is best for you.

Concrete mix to repair foundation


For all sinkhole repair, remediation, and filling services in the Maryville area, contact American Foundation & Waterproofing. We will handle all of your sinkhole issues with professionalism and expertise!