How to Fix Sink Holes in Sand

Fix sinkholes in sand with stone and gravel.

A sinkhole in the sand is a depression that can be shallow or deep, small or large. It is caused naturally by the deterioration of the limestone underground from too much rain, not enough rain or lowered water levels. Sinkholes in the sand, unlike other sinkholes, have a layer of sand that may be as deep as 50 to 100 feet. This type of sinkhole is called a cover-subsidence sinkhole and is usually small in size as the sand fills the cavities under the ground before they can develop and create a large depression. These small sinkholes can be filled with clean sand. Stones, gravel and geotextile fabric help to hold the sand in place. Each layer of stone, gravel and sand should be a minimum of six inches deep but enough to fill the hole.

Things You'll Need

• Large stones (about the size of a cabbage)
• Small stones (about the size of a fist)
• Gravel
• Geotextile fabric
• Coarse sand
• Sand
• Shovel
• Wheelbarrow
• Work gloves

Instructions

1. Fill the bottom of the sinkhole with a layer of large stones.

2. Shovel a layer of smaller stones on top of the large stones.

3. Shovel a layer of gravel on top of the smaller stones.

4. Place a geotextile fabric over the top of the gravel.

5. Shovel coarse sand over the geotextile fabric until it is covered.

6. Fill the remainder of the hole with sand similar to the sand in your yard.

Tips & Warnings

• It may be necessary to add a top layer of sand again later, but eventually the hole should stabilize.

• If the hole is a threat to your house or other structure, call your insurance company to report it. Your insurance company may cover the cost for repairs.

• Wear work gloves to protect your hands.

• Rope off the sinkhole until it is filled to keep children and pets from falling into the hole.

References

• Florida Department of Environmental Protection: Sinkhole Questions
• Home Safety Sinkhole Information
• EnviroSci Inquiry: Sinkhole Repair

Resources

• Geotextiles