Why is it important to use a metal base plate on footings?

Using a metal base plate on footings is crucial for several reasons, particularly in regards to stability and compensating for shrinkage. The metal base plate serves to distribute the load from the structure evenly across the footing, which helps to prevent shifting or settling that could occur over time due to soil movement or changes in moisture content. This is especially important in regions where the ground may expand or contract with varying temperatures and moisture levels.

Additionally, the plate can help to mitigate issues that arise from soil shrinkage, such as when clay soils dry out and lose volume, potentially causing the footing to sink or shift. By providing a stable platform, the metal base plate enhances the overall integrity of the foundation system, ensuring that the structure remains level and secure even in the face of these environmental factors.

Other options, while they may have some relevance to the use of base plates in certain contexts, do not accurately capture the primary function and significance of a metal base plate on footings as pertains to stability and soil dynamics.