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

Soil condition is a critical factor in deciding between a slab on grade foundation and a grillage foundation.

A slab on grade foundation is typically more suitable for stable, well-draining soils where the ground conditions can support the weight of the structure with minimal settlement. This type of foundation is often used on sites with competent subgrades that can adequately handle moisture and load distribution.

In contrast, grillage foundations are often employed in situations where soil conditions may not be ideal for a slab on grade. For instance, if the soil is weak, compressible, or prone to significant movement under load, the grillage foundation helps distribute the weight of the structure over a larger area, minimizing the risk of settlement and structural failure.

Choosing the right foundation type based on soil condition is crucial for ensuring the stability and longevity of the construction, making it the most pertinent factor in this context.