Sinkhole Repair MethodsSinkholes are common in Florida, and a scary problem for any home or business owner. When you discover one on your property, what should you do? Who should you contact? At Foundation Professionals of Florida, we’ve been repairing sinkholes since 1980.

Repairing Sinkholes: Grouting or Underpinning?

There are two primary ways to fix a sinkhole: grouting and underpinning. After a careful inspection of your sinkhole, our team will select the right sinkhole remediation method.

Grouting involves injecting grout into the soil in order to stabilize it. It stops the soil from shifting or moving, and fills voids created by sinkhole activity. At Foundation Professionals of Florida, we use both cement and chemical (polyurethane) grouting.

Cement Grouting

Cement grouting involves injecting a cement-based grout into the sinkhole via steel casings. We use high pressure to pump the grout deep underground. Shallower parts of the sinkhole can often be filled with a wetter cement mixture. This method fills voids and seals limestone. Cement grouting also provides the residence, structure, or roadway with a denser, more stable soil base.

Chemical Grouting

This type of grouting is also known as polyurethane grouting. It involves injecting a resin (usually polyurethane) into a sinkhole in order to fill the void. The polyurethane resin expands into an inert foam, and lifts and stabilizes the slab or floor. The amount of pressure and expansion depend on the type of chemical compound used.


Underpinning involves stabilizing and releveling a structure through the use of steel piers. The piers are installed until they reach load-bearing soil, and then the concrete slab or foundation is hydraulically lifted. Underpinning does not fix the sinkhole, it fixes the damage to the structure caused by the sinkhole. Therefore, underpinning is a solution that’s sometimes used in conjunction with grouting.

Which solution we use depends on a variety of things including the damage caused by the sinkhole, and the makeup of the land underneath the affected structure.

Different Types of and Causes of Sinkholes

First, we will assess the damage and figure out what kind of sinkhole you have. There are three main types of sinkholes:

Dissolution or Solution Sinkholes

This kind of sinkhole forms slowly. Dissolution or solution sinkholes happen when there is not very much soil or vegetation covering the limestone or bedrock. Water slowly flows over the bedrock and dissolves it. This results in a depression that might become a pond if it gets lined with debris. Surface water then fills the crevices in the limestone and slowly dissolves it, forming a sinkhole

Subsidence Sinkholes

This type of sinkhole occurs when rainwater soaks through sediment to reach the limestone, dissolving it and weakening it. These sinkholes are formed naturally over time, as small cracks in the limestone grow wider and wider due to erosion. Sediment from upper layers of land fill the cracks and a depression forms at the surface of the ground.

Cover Collapse Sinkholes

These sinkholes collapse quickly and can be very dangerous. With this kind of sinkhole, there is usually a layer of clay under the ground cover and above the bedrock. Sediments from the ground level erode over time, and when only a thin layer remains, a sinkhole can open up quickly, revealing the underground void that has been forming.

Some sinkholes are also formed by human activity, such as pumping of groundwater during freezes to prevent crop damage, excavating, well drilling, landfill creation, broken water lines or leaks, and pounding or blasting for construction or mining.

What You Should Do if You See a Sinkhole

The most important thing you can do in case of a sinkhole is call the experienced team at Foundation Professionals of Florida as soon as you see one, or if you notice warning signs. Warning signs include:

  • Slumping of the ground
  • Leaning trees or fence poles
  • Subsiding soil
  • Exposed foundations or tree roots
  • Structural cracks in doors, windows, or walls
  • Foundation settlement
  • Wilting vegetation in circular patches
  • Small ponds or depressions
  • Deep vertical holes of all sizes

If you notice any of these problems, call us right away. We have over 38 years of experience in geotechnical sciences and are equipped to handle any kind of sinkhole. Do not let a sinkhole endanger your home or family. Contact us today for all of your sinkhole repair needs in Florida.