04/06/2026
Foundation compaction is the process of increasing the density of soil beneath and around a building foundation by reducing air voids in the soil. Proper compaction improves the soil's load-bearing capacity and reduces settlement, helping prevent foundation problems such as cracking, uneven floors, and structural movement.
Why foundation compaction is important
Increases soil strength and stability
Reduces future settlement
Improves foundation support
Minimizes water infiltration and erosion
Helps prevent structural damage
Typical construction process
1. Excavate to the required foundation depth.
2. Place soil or fill in thin layers (often 150–300 mm thick).
3. Compact each layer using suitable equipment.
4. Test the compaction level (for example, using a Proctor density test or field density test).
5. Continue until the required density specification is achieved.
Recommended compaction levels
Many building projects require soil to be compacted to 90–95% of the maximum dry density determined by a Proctor test, though the exact requirement depends on the engineering design and local authorities codes.
