Which material is NOT commonly used in foundation construction?

In foundation construction, materials are selected based on their structural properties, durability, and ability to support the weight of the building above. Concrete is a primary choice due to its strength and resilience against weathering and loads. Cinder blocks are also commonly used, as they are versatile and can be easily formed into walls that provide support for a foundation.

Wood is occasionally used for foundations, particularly in specific types of construction like pier and beam foundations, where wood piers elevate the structure above the ground. However, it is less common in traditional foundation settings compared to concrete and masonry materials due to wood's susceptibility to rot and insects.

Straw, while an environmentally friendly building material in some contexts, such as straw bale construction, is not appropriate for foundation purposes. It does not provide the necessary structural integrity or resistance to moisture that is critical for a material used in a foundation. Thus, straw is not commonly used and is the correct answer to identify a material that does not belong in standard foundation construction practices.