When to choose soil injection over re-foundation

When settlement appears in an existing structure, the first instinct is often full re-foundation — an expensive, slow fix that usually means evacuating or shutting down the building. In a large share of cases, that's not actually necessary.

Soil injection, whether cementitious or chemical, treats the problem at its source: voids or weak soil beneath the foundation. Compaction grouting fills these voids and gradually densifies the soil, while polyurethane chemical grouting expands quickly and lifts the structure with millimetre-level precision.

The choice between injection and re-foundation comes down to specific factors: the depth of the weak soil layer, the magnitude of settlement, and the structure type. Settlement from collapsible soil or localized voids is usually treated successfully with injection, while settlement from a fundamentally inadequate foundation may call for other solutions such as micropiles.

The first step is always a precise geotechnical survey. Without it, any decision — injection or re-foundation — remains an expensive guess.