Sinkhole Warning Signs Around Your Property


Knowing the early sinkhole warning signs around your property can save you thousands in foundation repair costs down the road.  The sooner you can identify your potential foundation problems, the easier it is to fix them. Sinkholes can appear to have opened overnight, but the majority of them evolve over time, developing long before any surface evidence is detected. Areas where there is a lot of underground rock and clay soil are ideal for sinkholes. A common misunderstanding is that a sinkhole is the actual hole in the rock. But in reality, the sinkhole is what we see on the ground surface because of the hole in the rock below. If you are experiencing a number of these signs, please contact Helicon for a sinkhole repair inspection. 

Monitor the Inside of Your Home For Sinkhole Warning Signs

Houses settle over time, and a little unevenness isn’t cause for panic.  At the same time, you’ll want to be alert to these warning signs that more dramatic changes are taking place:

  • A door begins to jam or fails to latch
  • Cracks appear in walls, especially over doorways, windows or where walls meet ceilings.
  • Cracks open in vinyl or ceramic tile over a concrete floor
  • Windows that used to open and close easily suddenly begin to stick or won’t close completely
  • Cracks in interior joint areas
  • Uneven kitchen cabinets and drawers
  • Slanted floors
  • Water leaks or flooding when it rains
  • Stairs begin to slope
  • Nails begin to pop
  • Displaced moldings
  • Wet crawl space

Check Around the Outside of Your Home and Your Yard For Sinkhole Warning Signs

Staying alert for the sinkhole warning signs on the inside of your house is crucial, but there are numerous sinkhole warning signs to look for around the outside of your home and yard as well:

  • Fresh exposures of fence posts, foundations or trees that result when the ground sinks around them;
  • Slumping, sagging or slanting fence posts, trees or other objects.
  • Small ponds of rainfall forming where water has not collected before.
  • Wilting of small, circular areas of vegetation. This happens because the moisture that normally supports vegetation in the area is draining into the sinkhole that is developing below the surface.
  • Cloudy water is pumped from nearby wells where the water was previously clear.
  • Depressions in your yard or street
  • Deep cracks and separation of paved concrete walks and drives
  • Neighbors have had or confirmed possible sinkhole activity
  • Pooling of water around foundation
  • Sinking front porch
  • Leaning/cracked chimney

Obtain a Free No Obligation Evaluation

Contact Helicon to see how Helicon’s dedicated Business Development Team can:

  • Determine the best options for foundation stabilization.
  • Help guide you through the insurance claim process.
  • Streamline communications with all involved.
  • Deliver a World Class customer experience.

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What are common sinkhole signs to be aware of?

  • Cracks in the walls
  • Cracks around the door or window frames
  • Cracks in the floor or pavement
  • Cracks in and around the pool area
  • Cracks in the foundation or the structure separating from the foundation
  • Not being able to close doors and windows correctly
  • Pooling of water on the property
  • Slumping or slanting trees or sagging fencing
  • Wilting vegetation in small circular areas

But, what even causes them to begin with? Ruptured sewer lines contribute to some urban sinkholes, but generally they are naturally recurring phenomenon characterized by sudden settlement or collapse of land. Most of the time, they happen when underground water or seismic activity creates voids or chasms underneath the surface of the earth. When topsoil becomes heavy with rainwater, or is subject to some other stressor, or even simply from gradual groundwater erosion, the surface collapses into the void, and a sinkhole forms and swallows whatever was sitting on top of it.

Areas built on soft rock, such as limestone, and near underground aquifers are particularly susceptible to sinkholes. While they are found all over the world, the area’s most at risk in the United States are here in Florida along what many call Sinkhole Alley representing Hillsborough, Pinellas, Pasco, & Hernando Counties. 


Sinkhole Locations

Florida residents can look here to see where subsidence reports have been filed in their neighborhood. Click on the button below.

View Sinkhole Map

What Causes Sinkholes?


More specifically, sinkholes are the result of water collecting underground and lacking external drainage of some sort, according to the U.S. Geological Survey (USGS). As the water collects and circulates, it slowly erodes the bedrock and creates caverns and underground spaces.

Water can erode just about anything given enough time, but soluble minerals and rocks, like evaporaites (salt, gypsum) and carbonates (limestone, dolomite), are particularly vulnerable and can be worn away more easily than some other types of rocks and minerals.

Over time — often a very long time — these caverns grow and grow until the very top layer of the ground is no longer supported. Then the ground opens up and swallows anything sitting there, and you have a sinkhole.

Adding additional weight on the surface, be it buildings or just heavy rainfall, can break the top of such a cavity and create a sinkhole.

making of sinkhole

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 What are the types of sinkholes?

1. Dissolution sinkholes. These sinkholes are the result of there not being much groundcover, like vegetation, over the bedrock. Water slips through pre-existing holes in the bedrock and begins to circulate through the bedrock. A depression in the ground can form, and if the bedrock layers beneath are sturdy enough or there's enough debris blocking the flow of water, the sinkhole may stop deepening. This could result in the formation of a pond-like areas and even wetlands, according to the USGS.



2. Cover-subsidence sinkholes. These sinkholes start with something permeable covering the sinkhole while also containing a good deal of sand. This sediment begins to spill — or spall as the proper nomenclature refers to it — into those empty caverns among the bedrock. Over time, a depression in the surface may occur. This sediment can block the caverns and prevent the flow of water. These sorts of sinkholes are never very large, according to the Southwest Florida Water Management District, since the sediment prevents the water from further eroding the surrounding bedrock.

3. Cover-collapse sinkholes. Perhaps the most well known of sinkholes, cover-collapse sinkholes are also the most dramatic. The surface area above the bedrock in this instance is mostly clay, spalls into the cavities. But since the clay is sturdy, arches form as it slowly spalls. This arch continues to support the surface ground until it becomes so thin that it collapses into the cavern below, swallowing up everything above it.

There is one final type of sinkhole, and that's man-made sinkholes. These sinkholes are the result of a variety of practices, from drilling to mining to changes in water diversion systems to broken pipes.

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Can we predict when sinkholes will happen?

While sinkholes have a reputation for being sudden occurrences, they happen over long periods of time. This means there are sometimes signs that a sinkhole could be forming under your feet.

If you're looking for signs of a sinkhole below a building, the University of Florida recommends being aware of structural cracks in walls and floors, cloudy well water and doors and windows that won't close properly.

On the ground, there are likely to be more signs, including wilting or dying vegetation, previously buried things — like fence posts, roots or structural foundations — becoming visible, the formation of new and small ponds and slumping trees and fences.

Should a sinkhole occur near you, the Southwest Florida Water Management District recommends evacuating the premises and then notifying your insurance agency and the city.

How can you protect your property?

The most important thing to keep in mind is the structure of your insurance and risk management plan. Standard landlord and multi-family structural insurance policies do not normally cover sinkhole risk. If you look in your policy, you’ll almost invariably find sudden earth movements to be excluded. Because the sinkhole risk is not relatively uniform from location to location, you must normally purchase sinkhole coverage separately, just as you do with flood, earthquake and windstorm insurance. If you aren’t covered, and your property is damaged thanks to a sinkhole, you’ll be out of luck.

Some states, including Florida and Tennessee, require that property insurers offer it, but you may have to opt-in. In Florida, which has a lot of multi-family dwellings and over 19,000 identified sinkholes, insurance companies must make it available for an additional premium.


Residential property insurance companies can issue sinkhole policies with deductibles of 1 to 10 percent of the value of the property. In Florida, these policies define sinkholes as “catastrophic ground cover collapse,” meaning “geological activity that results in all of the following:

  1. The abrupt collapse of the ground cover;
  2. A depression in the ground cover clearly visible to the naked eye;
  3. Structural damage to the covered building, including the foundation; and
  4. The insured structure being condemned and ordered to be vacated by the government agency authorized by law to do so.

As with flood insurance, you should assess structural building insurance and contents coverage separately, especially if you’re leasing furnished apartments. This was a big concern for the Summer Bay Resort, of course, since it’s a vacation destination and therefore the owners had a substantial investment in furnishings in each room.

Your tenants should secure their own renters insurance policy if they want their belongings covered in the event of a sinkhole destroying their personal property. (Note: those occupying structures damaged by sinkholes should not assume they’ll be able to recover their property. Tenants in some situations never were able to recover their personal belongings).


How do I tell if I might have a sinkhole?

Sinkholes usually take people by surprise. But there are some early warning signs that may occur before a catastrophic ground cover collapse. Below are some signs of possible sinkhole activity. The more that you have, the more important it is to have your home inspected and evaluated immediately.

  • Do any of your doors (including screen doors) have trouble closing or opening?
  • Do any of your windows "stick" and “jam” or can be tough to open?
  • Does your electric or water bill seem too high?
  • Have you experienced any odd plumbing problems on your property?
  • Are the cabinets and drawers in your kitchen and bathroom normal and level?
  • Has a gap formed between your kitchen/bathroom counter backsplash and the wall?
  • Have any shower tiles loosened, cracked or popped off?
  • Is there any separation, or gaps, between any of your walls and the ceiling?
  • Is there any separation, or gaps, between any of your walls and the floor?
  • Are there any cracks in your interior walls?
  • Is there cracking or cracks around the corners of door and window frames?
  • Do you have any cracked or "hollow" sounding floor tiles?
  • Are there any cracks in your floor in common areas?
  • Does your floor feel level?  (Tip – put a golf ball or marble on different spots on a hard floor and see if it rolls anywhere)
  • Are there any odd water spots or discoloration in any walls or ceilings?
  • Have there been any water leaks or flooding when it rains?
  • Do you have any cracks in your driveway or streets inside the complex? How wide are they?
  • Do you have any cracks in your exterior walls? How wide?
  • Do you have any cracks around windows?
  • Do any cracks look like “stair steps” going up or down?
  • Do you have any cracks in your garage walls, floor or ceiling?
  • Are there any "normal settlement" cracks that seem to be growing?
  • Have any of the cracks grown longer or wider?
  • Do you have any loose or odd roof tiles?
  • Do you have any "dead patches" of grass or shrubs in your yard?
  • Does your yard slope in any direction?
  • Are there any slight dips or depressions in your yard?
  • Are there any holes in your yard?
  • Has your fence or retaining wall moved, shifted, or cracked?
  • Is there a lake, canal or drainage pond nearby?
  • Previously underground areas of fence posts, trees and the building foundation itself that is now exposed. This means the ground around them is sinking.
  • Ponds collecting in new places after rainfall.
  • Deep, narrow holes down to the aquifer.
  • Have any units in your complex had sinkholes?
  • Have any neighboring buildings had a sinkhole?

I might have a sinkhole. Now what?

If you inspect your property and find signs of sinkhole damage, the next step is to call your insurance company. Before you do so, have a copy of your insurance declarations page handy. 

Keep the initial call short and sweet. They will ask you a series of questions. Probably just name, policy number, what type of damage you are seeing and when you first noticed it. 

Important note: You will also need to determine a "date of loss" or a date that the damage occurred. If the damage occurred before you bought your home or purchased that policy, your claim might be denied. (Read between the lines.)

Even if my property has some of these signs, is it possible that I do not have a sinkhole?

Thankfully yes. Many of these damages can be caused by settling of the home or a loose joist on your foundation. Your insurance company will do an inspection, but keep in mind that sometimes insurance companies will blame other causes incorrectly.

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How Do I File A Sinkhole Claim?

Start right away! Secure your property and take all steps necessary to protect yourself and others from danger/potential harm. Review your Insurance policy for sinkhole coverage to put in a claim. In Florida, if you have sinkhole insurance coverage, your insurance company is required by law to cover damage related to sinkhole activity (up to the limits of your policy). You can then decide to call your insurance company or agent on your own and let them know what has happened and provide some basic information where they should begin the claims process.

Your insurance company will generally send an engineer or geologist to survey the damage and to conduct sinkhole testing. Initial testing for sinkhole activity may consist of ground penetrating radar and electrical resistivity studies. These tests are used to detect anomalies underground. Another test that may be conducted is called standard penetration testing, where a drilling rig is used to bore a hole into the earth. Sinkhole testing usually takes several days but may be spread out over the course of several weeks depending on the type of test(s) conducted. If sinkhole activity is detected, your insurance company will request repair estimates, which should only come from licensed contractors. If sinkhole test results are negative (no sinkhole activity is found), your insurance company will most likely deny your claim.


Damages from sinkholes aren’t just limited to fixing or replacing structures affected by ground cover collapse. Property owners should also consider speaking to their insurance professionals regarding the following additional possible damages:

Business interruption. If you have to evacuate your whole structure, you won’t be collecting rent. Will you be able to make your monthly obligations without rental income coming from your tenants?

Utility Interruption. Suppose a sinkhole doesn’t damage the building itself? In Florida, it wouldn’t qualify using the state’s legal definition of sinkhole, which requires that the structure itself be damaged. But if it ruptures a gas or water main, or destroys your septic or sewage system, you still have a problem. Consider what an extended loss of communication, water, sewer, gas and electricity would do to your bottom line.


Now what is the process? What should you expect from your insurance company? What should you say or not say so that your claim has the best chance of getting approved?

Usually, within a few days, you will get a call from your adjuster. They will schedule an inspection and a time to talk to you. The inspection should take about an hour.

  • Clean up your property. Pictures will probably be taken, and just on case you end up in court you want to look responsible.
  • Think through what you will say. Don't get too chatty. The adjuster is working for the insurance company, not you. It is their job to prevent the insurance company from paying out unnecessarily. Answer the question with facts that you know and say as little as possible.
  • Don't guess. If you don't know the answer, just say so. If you don't remember, say you don't. There is nothing wrong with not remembering. 
  • Timeframes are important. If you noticed the cracks in your wall 3 weeks ago, say so. If you tell the adjuster that you have no idea how long they have been there, and that they have been there since you bought the house, they could deny your claim based on the possibility of pre-existing damage.

Your insurance company is obligated by law to have a testing company confirm or deny that sinkhole activity is causing damage to your property. You will probably get a notification from your adjuster that a testing company has been assigned and a call from the testing company to schedule a time for their visit. The testing will include a detailed inspection of your property, followed by different types of Geophysical tests such as radar and drilling.

The Report.

A few weeks after the testing, your insurance company will forward you a thick report. These are usually standard reports slightly modified for your situation. 

The Decision.

Not long after the report, you will be notified of the insurance company's decision. This should take a relatively short period of time. If it has been weeks or months since you have received the report, you may want to contact an attorney.

How to Select a Sinkhole Repair Company

Once you have made it through the sinkhole claim process and your insurance company has approved your claim, the repair process starts

This can raise many questions: 

  • How disruptive will this be to my life?
  • Will my property retain its value after the repairs are done?
  • How do I ensure that my tenants are safe during the process?
  • How long will this take?
  • What should I expect?

It will be your responsibility to get bids from sinkhole repair companies, as well as cosmetic repair contractors. The sinkhole repair company must be a state licensed, certified geotechnical or structural engineer. Your insurance company may recommend some. 

As sinkhole claims rise all over the state of Florida, and insurance companies continue to change the way they handle them, property owners have more and more questions about them.


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Questions to ask a sinkhole repair company

Are you licensed and insured?

This seems like a no-brainer, but unlicensed and uninsured contractors abound in Florida. It is important to check. Helicon is licensed for the entire state of Florida and has successfully completed thousands of commercial and residential projects.

Is your company a member of the Better Business Bureau?

If they are, check their ratings and reviews. We are listed on the Better Business Bureau and have a A+ rating. You can also check on Google, Angie’s List, Yelp, Facebook, and Houzz.

Is your company a full member of the Florida Association of Sinkhole Repair Specialists (FAS3)?

Helicon is a proud and active member inside FAS3 which provides engineers, geologists and contractors with up to date information about sinkholes, remediation processes, innovations and new equipment.

How many years of experience do you and your staff have in sinkhole repair?

Select a company whose primary experience is sinkhole repair. Many General Contractors with years of experience in general construction will take on sinkhole repair jobs when construction is slow. Work with someone who is focused on sinkhole remediation.

How up to date are your methods and tools?

You don't have to understand how everything works. You do want to know how well the company has kept up with new advances in the sinkhole remediation process. Ask them what equipment advances they have made since they have been in business.

May I speak with some of your customers?

If the company is reputable, they should be able to give you some verified testimonials. You may be able to walk a job site with a foreman.

A sinkhole repair company will be in and around your property for a few weeks, maybe even a month during the repair process. For this reason, it is important to select one that you are comfortable with. After you have considered the "hard facts", consider how the company representatives made you feel about the process. Were you given a hard sell, or did they seem to want you to be an informed customer? Trust your gut.

The Bottom Line

If you’re in sinkhole alley, take nothing for granted. Read your landlord’s insurance policy or commercial insurance property and understand the details, including how your policy defines sinkhole/ground cover collapse hazards and what is and isn’t excluded. If your property is geologically at risk of sinkhole damage (which isn’t limited to Florida), expect to buy separate coverage, just as you do with flood insurance or windstorm/hurricane insurance.

When to Bring in the Best

Helicon is the premier geotech construction company in Florida. Based out of Tampa, FL. we are a licensed general contractor leading the industry in full-service geotech construction work.

We are experts in pre-construction, soil and structural stabilization, & sinkhole repair. As the premier provider of geotech construction services throughout the state of Florida for nearly 15 years, Helicon prides itself on providing high quality service, for both insurance companies and private customers with handling all repairs and pre-construction work for both residential and commercial projects. We strive to exceed everyone’s expectations.

Helicon has successfully completed thousands of projects in the state of Florida with a focus on the Tampa Bay metropolitan area, including the surrounding counties of Hillsborough, Pinellas, Pasco, Hernando, Polk, Citrus and Marion counties. Our professional Helicon Teams are trained and equipped with the tools and expertise needed to execute a flawless and professional experience using the latest technology to repair or prevent for your particular project.

We invest in our teams ensuring they remain up to date on the latest industry technology and training. Our Office Teams will answer all your questions, provide professional service, give knowledgeable advice, and execute a project that will fully satisfy our customers.


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