When a sinkhole opened beneath a family home in Palm Harbor, FL during the middle of the night, it was a terrifying experience for the homeowners. The Palm Harbor area—like much of Florida—is known for karst geology and unstable soils that can lead to sinkhole formation.

Before Helicon began our work, emergency crews placed flowable fill into the sinkhole to temporarily stabilize the collapse and make the site safe. This initial step allowed us to move forward with a comprehensive, permanent repair plan.

What made this case unusual was the lack of warning signs. Many sinkholes present symptoms beforehand—such as cracks in walls, sticking doors, or depressions in the yard—but in this case, there were minimal to no visible indicators.

The homeowners contacted Helicon for an emergency foundation stabilization. Our mission was to restore the property to safe, stable ground and give the family the confidence to live in their home without fear of recurrence.

This was a large-scale sinkhole remediation project that spanned from February to August 2024. The scope involved:

• Coordinating with engineers, geotechnical specialists, and construction crews
• Managing tight deadlines so the displaced family could return home quickly
• Working both inside and outside the home without compromising safety
• Addressing community concerns—neighbors were understandably worried about potential sinkhole activity in surrounding properties

Due to the extent of the soil instability, the family was required to relocate during repairs, adding urgency to the timeline. Helicon also conducted community outreach, encouraging nearby homeowners to have their properties evaluated for early signs of sinkhole activity.

Step 1 – Drilling & Casing Installation

Our crews drilled 4,560 linear feet of casings in key interior and exterior locations. These casings serve as the channels for compaction grout injection, targeting the deepest and weakest soil zones down to bedrock.

Step 2 – Compaction Grouting

A total of 700 cubic yards of high-strength compaction grout was injected into the casings. This grout:

• Densifies loose soil layers
• Displaces voids
• Bonds directly to solid limestone bedrock for maximum stability

This step is critical for large-scale sinkhole repairs, as it strengthens the load-bearing capacity of the soil beneath the structure.

Ground Penetrating Radar (GPR) Scan

We conducted a GPR Scan to map underground conditions, locate voids, and verify grout penetration, ensuring full coverage and eliminating weak points.

Step 3 – Chemical Grouting for Surface Stability

After deep soil stabilization, we addressed near-surface soils and foundation zones using 2,455 pounds of two-part polyurethane chemical grout. This lighter, fast-expanding foam is ideal for:

• Filling smaller voids near the foundation
• Stabilizing pool decks, patios, and slabs
• Providing an additional layer of protection against minor settlement

The Results

By the project’s completion, the home’s foundation was fully stabilized from bedrock to surface level. The family could safely return home knowing:

• The underlying soils had been reinforced to resist future sinkhole activity
• The property’s value and safety were restored
• Preventative measures were in place to protect against soil washout and void recurrence

Why Sinkholes Happen in Palm Harbor & Tampa Bay

Sinkholes are a natural geological hazard in Florida’s limestone-rich terrain. Common causes include:

• Dissolution of limestone from acidic rainwater and groundwater
• Water table fluctuations during droughts and heavy rains
• Underground void expansion leading to surface collapse

Palm Harbor, Clearwater, and the surrounding Pinellas County area are high-risk zones, making proactive soil evaluation and stabilization critical for homeowners.

Helicon – Florida’s Sinkhole Repair Experts

Helicon has decades of experience repairing sinkholes, foundation settlement, and unstable soils throughout Florida. We combine engineering-grade stabilization techniques with precision execution to restore structural integrity in even the most extreme cases.

Contact Helicon today to schedule a sinkhole evaluation: www.heliconusa.com/contact