Are there common causes of settlement damage?
During most sinkhole investigations, engineering firms examine the deeper soils as well as the soil material in the shallow areas near the home. Sinkhole activity requires deeper borings, to depths as deep as 100 feet below the surface. The limestone is the primary area of concern, with an examination as to whether the rock is dissolving. At the same time the limestone is being examined, most engineering firms will also do shallow borings, called hand augers, to extract the surface materials for expansive clays or organic material. (Read more about what constitutes a sinkhole.)
Things to Keep in Mind if Expansive Clay Soil Is Found
The issue of expansive clay soils, or “shrink swell” clays is a common distraction for deciding whether a home is being impacted by sinkhole activity. If you or someone you know has been told there is no sinkhole activity and the damage is being caused by expansive clay, here are the most important things to keep in mind:
- Even if expansive clay soil was found at the site, this does not mean the home is not being impacted by sinkholes. This is complicated, but it is associated with the manner in which expansive clay and sinkholes are formed.
- Many sinkhole investigations are “denied” claims more because they are incomplete, not because they necessarily excluded sinkhole. Thus, while the sinkhole investigation may not be complete, the presence of expansive clay soil often results in a denial of the claim simply because they found clay near the surface.
- Lastly, for expansive clay to be the cause of the damage, several things have to be true:
- It has to be of a particular kind.
- It must be at a particular depth.
- It must be of a sufficient percentage of the soil to actually impact the movement of the home.
Suffice to say, we read a lot of engineering reports where the insurance dispute can be found quickly. If we see something we do not fully understand on technical matters such as this litmus test applied to the presence of expansive clay soils, then we can find an appropriate professional who can assist our clients.
Have a burning question you’d like to ask about sinkholes? Let us know.