Voids under concrete slabs are caused by various things including,

  • Erosion – Excess water around a concrete slab leads to soil erosion and then voids. Two common causes of erosion are drainage issues and leaky plumbing.
  • Soil settlement – Soil settlement is another cause of voids under a slab. Soil needs adequate compaction before you place something heavy on top of it. If it’s not compacted, the soil will compress unevenly after something heavy – like a concrete slab – is placed on it. This, combined with poor drainage, is a sure recipe for void formation. Settlement can also cause problems with drainage.
  • Freeze/thaw cycles – Seasonal temperature changes cause freeze/thaw cycles that contribute to erosion and void formation.
  • Clogged gutters and short downspouts – Excess water under the slab can lead to erosion if it cannot adequately drain off. Two causes of excess moisture are clogged gutters and downspouts that are too short and therefore unable to channel water away from the slab.
  • Drought – Soil will shrink if it dries out, and soil shrinkage often leads to voids. F
  • Hydrostatic pressure – When too much water under the slab can’t drain off, hydrostatic pressure will build up and push against the slab. This can cause it to crack and become unlevel.
  • Poor maintenance – Poor maintenance practices can also cause voids. For example, if you don’t fix cracks in the slab right away, rain will get under the slab and this could lead to erosion.
  • Burrowing critters – Even burrowing animals can contribute to void formation.


Pinnacle Concrete Solutions (Concrete Lifting Near Me) are your local experts for all your lifting, leveling and concrete repair needs in Connecticut and surrounding states. Concrete slabs that are cracked, sunken or uneven can be both dangerous and a liability on your property. If you’re looking to avoid safety hazards and restore the curb appeal of your sidewalk, driveway, pool deck, parking lot or any other concrete surface, the experienced technicians at Pinnacle Concrete Solutions can help.

As your regional Foam concrete lifting company, we have the experience, expertise and equipment to level your sunken concrete and return it back to a safe, stable position. Don’t hesitate to call us or contact us online to schedule an on-site inspection your free cost estimate in Connecticut or an area nearby.