Which of the following is NOT a characteristic of effective foundations?

An effective foundation is critical for the stability and longevity of a structure. One of the key characteristics of an effective foundation is its stability and rigidity; it is not designed to be flexible. Flexibility in a foundation could lead to structural issues, as it may not adequately support the loads applied to it and can lead to settling or shifting over time.

Well-drained foundations ensure that water does not accumulate, which could lead to erosion or weakening of the soil underneath. Distributing loads evenly is essential to prevent localized stress that can cause damage. Additionally, using durable materials is important to ensure the foundation can withstand environmental effects and support the loads it will encounter throughout its lifespan. These attributes are all crucial for an effective foundation, while flexibility is not appropriate for such a structural element.