How to Repair Voids in Dirt Around Your Foundation

Identify and Assess the Void

Locate the low spots by probing the soil with a long steel rod or using a level on the exterior footing; a hollow sound indicates a void. Mark the area and note the depth and extent before beginning repairs.

Excavate to Reach Solid Soil

Dig a trench around the marked zone, exposing the void and extending at least 12 inches beyond its edges. Remove loose material until you encounter firm, undisturbed earth that can support load.

Backfill with Suitable Fill Material

Use a graded, well‑compacted fill such as crushed stone, gravel, or a sand‑soil mix. Place material in 3‑ to 4‑inch layers, tamping each layer with a hand tamper or plate compactor to achieve at least 95% compaction.

Stabilize with Geotextile Fabric (Optional)

For larger or recurrent voids, lay a geotextile fabric over the backfilled area before the final layer. The fabric separates fill from surrounding soil, reduces erosion, and distributes loads more evenly.

Re‑grade and Drain

After the void is filled, re‑grade the soil away from the foundation with a gentle slope of 5% (approximately 6 inches per 10 feet) to direct water runoff. Install or repair gutters and downspouts to keep water away from the footing.

Monitor and Maintain

Check the repaired area periodically for settling or moisture accumulation, especially after heavy rain. Promptly address any new drainage issues to prevent future void formation.