What are Sinkholes?

A sinkhole can also be known to some as a sink, shake hole, swallow hole, swallet, or doline. A sinkhole typically is a natural depression or hole in the Earth's surface caused by karst processes — the chemical and rapid dissolution of carbonate rocks or processes for example in sandstone. Sinkholes may vary in size, and vary in form from bowls to chasms. Sinkholes may form gradually or sudden, and are found worldwide. The different terms for sinkholes are often used interchangeably. In the United States many sinkholes form in Florida and Tennessee. These are the only states that currently offer sinkhole insurance to help protect homeowners from sinkhole problems affecting the structure and sinkhole foundations.

Here is a picture of a sinkhole that formed near the dead sea.
The typical things that cause formation involve natural processes of erosion or gradual removal of bedrock usually called limestone by percolation in water or a lowering of the water table. In Florida near Homossassa, Hernando, Citrus, and Pasco counties - the limestone is closer to the surface of the water. Many homeowners in Florida experience cracking and soil erosion. The problems cause struture and physical damage to the home.

  How Sinkholes Develop in Florida and the Gulf Coast Sinkhole activity is a geologic function that naturally occurs over thousands of years.  Underlying Florida soils is limestone sometimes call bedrock.  Limestone is a porous kind and type of rock, and water passes through the limestone to the groundwater table.  Florida limestone is somewhat alkaline, and as acidic rainwater passes through it, the alkaline limestone slowly dissolves over time.  In fact, that is the literal legal definition of Florida sinkhole activity – just ask a sinkhole lawyer.  A Florida sinkhole is defined by Florida law as the dissolution of limestone by water.  Sinkhole activity doesn’t require an actual surface hole, so to speak – sinkhole activity can occur through the below ground movement of soils!  In fact, there are a lot of places to find out about sinkholes and information.  Additional sinkhole information can be found at wikipedia. http://en.wikipedia.org/wiki/Sinkhole, http://en.wikipedia.org/wiki/Sinkhole and at http://plants.ifas.ufl.edu/guide/sinkholes.html, http://plants.ifas.ufl.edu/guide/sinkholes.html.   When the limestone dissolves, gravity pulls the soils that are above the now dissolved void downward.  Check out the sinkhole website on sinkhole house cracks for more information. Florida’s Department of Environmental Protection also has http://www.dep.state.fl.us/geology/geologictopics/sinkhole.htm.
File a Sinkhole Claim with your Insurance Company
When a Florida homeowner sees they have damage to their home from possible sinkhole activity, many Florida homeowners with Florida sinkhole insurance elect to file a sinkhole claim with their homeowners sinkhole insurance policy.  Filing sinkhole insurance claims can be very complex, and Florida homeowners with sinkhole damage should research sinkhole insurance claims and be very careful if filing a sinkhole insurance claim on their own. Professional pubic adjusters who specialize in sinkholes can assist homeowners in filing sinkhole claims, and one of them, sink-hole.com has a sinkhole information resource for Florida sinkhole homeowners who want to file a sinkhole insurance claim.   Confirmed Sinkhole Claim After a sinkhole claim is filed and the sinkhole insurance company conducts its investigation, if the investigation reveals sinkhole activity is occurring at the home, the insurance company will often confirm sinkhole activity.  If a homeowner has confirmed sinkhole activity at their sinkhole home, the homeowner has a number of options ranging from repairing the sinkhole to negotiating a settlement.  Homeowners with confirmed sinkholes should research and learn more about their confirmed sinkhole options before making decisions.   Denied Sinkhole Claim Sometimes sinkhole testing reports on sinkhole homes come back as denying sinkhole activity.  In reality, not every home that shows sinkhole damage is really damaged by sinkhole activity (lots of things can cause cracking, for instance).  But many times, even though the insurance company has denied sinkhole activity, a review of the denied sinkhole testing report by an independent geologist or geotechnical engineer (kinda like a second opinion) will reveal that sinkhole activity is impacting the home; learn more about denied sinkholes and know your rights and options.  If a homeowner has seen their sinkhole insurance claim for sinkhole activity be denied, they should consult with an experienced sinkhole lawyer.  

Florida Foundation Repair
When a sinkhole occurs your foundation typically is unstable and soil needs to be stabilized. Florida Foundation Repair shows the different methods used to repair you home. Grouting is when the repair companies install injection points all around the perimeter of your home. The grout truck travels around the home to inject pressurized grout mix underneath the foundation to fill in the soils.

Chemical Grouting: Chemical grouting is like adding an additional coat to the grouting to repair a home with loose soils near the surface of the house. Chemical grouting utilizes an advanced polymer substance that fills the sinkhole and then hardens. Chemical Grouting gives long-term stability to the area affected by sinkholes.

Another method in addition to the repair is something called underpinning. Think of it like a "house on stilts." Underpinning attaches beams to the perimeter of the home to take the weight of the home off the soils and on to the more solid bedrock. Underpins are typically warrantied. Underpinning can be done on the permiter and the interior. Interior underpins are especially needed if the interior floor elevation is way out of tolerance.  

Other Links:

http://ga.water.usgs.gov/edu/earthgwsinkholes.html, http://ga.water.usgs.gov/edu/earthgwsinkholes.html, http://ga.water.usgs.gov/edu/earthgwsinkholes.html http://fcit.usf.edu/florida/maps/galleries/sinkholes/index.php   http://news.nationalgeographic.com/2010/06/photogalleries/100604-sinkhole-pictures-around-the-world-guatemala-city/, http://news.nationalgeographic.com/2010/06/photogalleries/100604-sinkhole-pictures-around-the-world-guatemala-city/, http://news.nationalgeographic.com/2010/06/photogalleries/100604-sinkhole-pictures-around-the-world-guatemala-city/   http://www.swfwmd.state.fl.us/hydrology/sinkholes/, http://www.swfwmd.state.fl.us/hydrology/sinkholes/, http://www.swfwmd.state.fl.us/hydrology/sinkholes/