A Clearwater homeowner experienced a cover collapse sinkhole in the front yard, only feet from the house. Unlike a subsidence sinkhole, which develops gradually, a cover collapse happens suddenly when the surface soils give way—leaving a dangerous void.

The collapse caused visible cracking and settlement in the home’s foundation, especially near the front corner. An engineer confirmed that immediate stabilization was required to secure the property.

Helicon was contracted to perform a comprehensive sinkhole repair, combining multiple stabilization techniques to permanently restore the home’s safety and value.

Several factors made this repair complex:

• Proximity to the home’s foundation – Cracking was already visible near the front corner of the
• Soil instability at multiple depths – Weak layers extended from shallow soils down to limestone
• Risk during drilling and grouting – Both drilling and high-pressure injections can create further soil movement if not carefully managed.

Additionally, Clearwater’s geology—limestone beneath sandy soils—creates conditions where cover collapse sinkholes can form quickly after heavy rains follow extended drought periods.

Helicon executed a three-phase stabilization plan, ensuring the home was fully secured from top to bottom.

Step 1 – Compaction Grouting 

• 1,035 linear feet of drilling reached depths of 30–50 feet to competent
• 200 cubic yards of grout were injected under pressure to fill voids and densify
• Grout injection points were installed every 10 feet around the sinkhole area for complete

Step 2 – Underpinning

To protect the structure after grouting, Helicon installed 12 underpinning piers around the compromised front corner of the house.

• 252 linear feet of steel piers were driven below the surface to transfer the home’s load to stable
• Steel brackets ensured the home was fully supported and prevented additional

Step 3 – Polyurethane Chemical Grouting

To stabilize the upper soils above 15 feet, Helicon applied polyurethane two-part foam injections:

• 500 pounds of material expanded into voids near the
• Created a dense, water-resistant layer to prevent erosion and shallow
• Worked in tandem with compaction grout for complete

The Results

By the project’s completion, the Clearwater home was:

• Fully stabilized from limestone depth to surface soils
• Reinforced by 200 cubic yards of compaction grout, 12 underpinning piers totaling 252 linear feet, and 500 pounds of polyurethane foam
• Secured against both deep settlement and surface soil collapse

The home is now safer and stronger than before the sinkhole appeared, backed by Helicon’s proven methods and warranty.

Why Clearwater Homeowners Choose Helicon

Helicon is the trusted leader in sinkhole repair and soil stabilization across Florida, partnering with engineers, insurance carriers, and homeowners to deliver lasting results.

Homeowners in Clearwater, Palm Harbor, St. Petersburg, and throughout Pinellas County choose Helicon because we provide:

• Comprehensive repair methods (underpinning, compaction grout, chemical grout)
• Proven results with zero reoccurrence on repaired sinkholes in over 20 years
• Peace of mind with stabilized, warrantied foundations that protect property value

Schedule a sinkhole inspection today: www.heliconusa.com/free-inspection-request