Void Form

A 4' x 4' x 4" void form is a construction material used to create voids or empty spaces within concrete structures, such as foundations, walls, and slabs.
It is typically made of extruded polystyrene foam (XPS), which is a lightweight and durable material with excellent insulation properties.

The purpose of a void form is to create a void or empty space within the concrete structure to reduce weight, save concrete, and provide a thermal break between the foundation and the surrounding soil.
The voids can also help to reduce the likelihood of cracking caused by shrinkage, settling, or expansion of the concrete.

Overall, a 4' x 4' x 4" void form is a useful construction material that can help improve the durability, stability, and energy efficiency of concrete structures.