Which factor can influence the choice between a slab on grade or grillage foundation?

The choice between a slab on grade and a grillage foundation is significantly influenced by soil condition. This factor is crucial because the type of foundation selected must appropriately respond to the properties of the underlying soil. For instance, if the soil has low bearing capacity or is highly compressible, a grillage foundation, which distributes loads over a larger area through a system of beams, may be preferred. Conversely, a slab on grade foundation might be suitable for stable, well-drained soils that can adequately support the load of the structure without excessive settlement.

Soil conditions encompass aspects such as bearing capacity, moisture content, and the presence of expansive clays or other problematic soil types. Therefore, a thorough geotechnical analysis is essential to determine the most effective foundation type, ensuring stability and longevity for the structure being built.