Once the sinkhole has stopped growing and remained the same size for a few days, you can fill it in.
Exercise caution when walking around the edge of the sinkhole! The ground can be very unstable, so take care not to fall. Do not attempt to fill in a sinkhole larger than 3 feet (0. 91 m) in diameter. [4] X Research source Large sinkholes can be deep and potentially dangerous. If the sinkhole is deeper than chest height, do not step down inside of it. Deep sinkholes, and holes with steep walls, pose a high risk of collapse. [5] X Research source
Landscaping companies will have more experience in dealing with this phenomenon than the average homeowner. When dealing with very large sinkholes, you’ll need to contact local authorities in the city or county in which the sinkhole has appeared.
Also remove any loose debris that may be in the sinkhole: tree branches, pinecones, etc.
You can buy 80-pound (36 kg) bags of quick-mixing concrete at your local hardware store or home-supply store. The size and depth of the sinkhole will determine how much concrete you need to mix.
You do not need to let the concrete dry before you move on to filling the hole with sand and soil. A “plug” simply means that you’ll fully fill the bottom of the sinkhole with concrete.
Sand can be purchased at most large hardware stores, home-supply stores, or landscape-supply stores. If none of these venues sell clayey sand, contact a building contractor in your area. Most contracting companies will have a sand supplier that they may put you in touch with.
Topsoil can be purchased by the bag at any gardening center or home-supply store.
Repeat this process more than once, if necessary. The materials filling the sinkhole are likely to settle following heavy rain or runoff. Avoid planting trees or shrubs over the sinkhole as the may not thrive due to a lack of nutrients in the soil. They could also become uprooted or fall if the hole collapses again.
