Tag Archives: Expansive Clay

Grout Cracks and Sinkhole Damage

What causes grout cracks, and how do I know if they’re the result of sinkhole damage?

Sinkholes and sinkhole activity are associated with the movement of soils, into areas created after the underlying rock is dissolved. When the rock beneath the home deteriorates, it weakens and fails to provide the support needed from the initial construction of the home, causing grout cracking, among other problems.

In so doing, the house no longer sits on a level, competent base but instead is prone to shifting, settling, cracking, and even heaving, as the weight distribution in the foundation occurs. This is why sinkholes may actually cause some portions of the home to appear to rise, as the foundation is pushed upwards toward the sky. This is because another, less prominent area is shifting down and causing the other area to rise.

Grout Cracks in Some Counties Are More Suggestive of Sinkhole Activity

For most homeowners, the damage can be very subtle. In counties where sinkhole damage is common – such as Marion, Hernando, Pinellas, and Pasco – homes are most likely to present cracking in unusual places, such as at wall joints in the interior, or in stucco on the exterior of the structure. The significance of this is that the home is losing the support provided by the soil beneath the home, causing the perimeter to shift and crack.

Observing grout cracks in a “stair step” formation on the exterior of the home along the grout lines of block is a significant sign of sinkhole activity. While counties or cities like Marion or Ocala often have other, plausible explanations for such damage (e.g. expansive clay, organic soils, loose surface soils), these alternative explanations do not rule out sinkhole activity as a cause. Most often, these kinds of other causes are working side by side, to create the appearance of sinkhole damage.

What is a sinkhole, according to Florida law?

Have a burning question you’d like to ask about sinkholes? Let us know.

When Expansive Clay Soil Damage Constitutes a Sinkhole Claim

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:

    1. 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.
  1. 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.
  2. 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.

Sinkhole Investigations and New Home Construction

I’m in the process of closing on a lot that we intend to build our dream home on. What can we do before construction to make sure we don’t have a sinkhole problem?

I speak personally to this issue. I signed a contract for a new home to be built. We asked to conduct testing on the lot before we closed, and were denied this right until we closed on the lot, but before we began the actual construction. Two weeks later, after to Standard Penetration Tests, we found patent evidence of sinkhole activity. We worked it out with the contractor, who permitted us to cancel the agreement with them.

Conducting sinkhole investigations is costly, but it may be more costly not to. Consider this: Doing two standard penetration tests cost us $3,000, but that money was well spent because it saved us a great deal of money in the long run. If you are interested in conducting a sinkhole investigation, you need to have the testing done prior to the pouring of the foundation. The important thing would be to look at the footprint of the house and test in that area. If you provide the engineering firm the building plans, they will be able to recommend the testing locations.

Also, do your own sinkhole investigation of your adjacent property owners. Ask them if they have had any problems with settlement or if they have ever filed insurance claims. While this may be a bit forward on your part, people will often share their experiences, especially because it will often include complaints about problems with insurance companies.

Lastly, you will want your engineering firm to also conduct some shallow soil work, in the form of hand augers to a depth of about eight feet. This is because you will want to determine if you have any other, soil-related problems, as well as sinkholes. Problems with excessive organic material, expansive clay, or poorly consolidated sand can also cause significant problems for you.

As always, if you have any problems locating an appropriate engineering firm, we can offer you several options. Good luck.

Read our tips on filing a sinkhole claim.

Have a burning question you’d like to ask about sinkholes? Let us know.

Soil Conditions That Mimic Sinkhole Damage

Is there anything we can do to make sure we don’t have a sinkhole at our home?

Sinkholes are associated with the dissolution of the limestone layer beneath your home, which could be dozens of feet below your home. The hydrology of the soils near your home could be impacted by water that is not even within the first 20 or 30 feet below your home. Thus, the short answer is no, you cannot impact sinkholes on your property.

Having said that, you can have a positive impact on the soil near your home to easily reduce other problems. Believe it or not, you need to “maintain” the soils near the footprint of your home. Soils will become unstable if they experience long periods of drought or saturation. These extreme conditions can cause the soils near your home to greatly increase or decrease in volume. In so doing, they can directly impact your home. While these issues are not associated with sinkholes, they are associated with other conditions that can cause cracking or other distress to the home.

Soil conditions, such expansive clay or organic debris in your soil, can cause cracking. By making sure, for example, that the downspouts near your home are moving the water away from your home is important. Having the water flow away from your home (called “negative slope”) assures that water is not pooling around your foundation. If the water is running toward your foundation, you should consider changing the topography near the home, in a way to move the water away. During periods of dryness, you should regularly water your lawn, which also waters the soil. These simple steps can go a long way toward properly maintaining your home to avoid settlement problems.

Read our tips on filing a sinkhole claim.

Have a burning question you’d like to ask about sinkholes? Let us know.

Not All Foundation Repairs Covered by Sinkhole Insurance

When sinkhole insurance won’t repair your foundation

To homeowners, the actual cause of damage to their home is not their primary concern. Instead, they are interested in resolving any settlement damage to the property regardless of whether it is associated with sinkhole activity or another, more exotic explanation.

However, because home insurance policies in Florida specifically exclude home foundation repairs that aren’t caused by sinkhole activity, a homeowner’s understanding of these other alternative explanations is crucial.

How clay can cause damage

The most common explanation for settlement damage, other than sinkhole activity, is commonly referred to as “expansive clay.” This explanation is best understood by understanding how a sponge takes on water.

When water is poured onto a sponge, the water occupies the spaces between the pores, causing the sponge to expand in volume. When the sponge dries, the water wicks out and the sponge returns to its original state. That is what can happen to your home, necessitating home foundation repairs.

The same event occurs with clay. Clay, unlike ordinary soil material, has pores in it, into which water can occur space. In some instances, the water can actually trigger a chemical reaction in the clay, which causes it to change characteristics and volume.

When a clay area beneath a home becomes extremely dry, it loses its volume. When the water returns, the clay expands and causes it to move. Ordinarily, when homes and other structures are built, the soil beneath them is expected to remain stable. However, if the contractor fails to make sure the soil beneath the home is not overly clayey, the movement of the soils due to volume changes can result in cracking damage and subsequent very expensive house foundation repairs.

Why this is important

Understanding the common confusion between clay and sinkhole is important too because a clay condition in the soil can also be an indicator of previous sinkhole activity. These kinds of differences serve as a common sticking point between a homeowner and their insurance companies and often require the retention of a sinkhole lawyer.

Therefore, if you’ve submitted a claim with your sinkhole insurance company and they respond with a denial on the basis of the soil being clay, you may still have a chance at getting your home’s foundation repaired.