What Is a Foundation in Construction?

A foundation is a structure, usually made from concrete, that supports and anchors a building and conveys its weight directly to the ground. Foundations usually extend below the frost line to avoid damage from repeated freezing and thawing.

History

• The history of foundations precedes even Biblical times as mankind dug foundations for habitation as soon as they crawled out of the caves. While the very first foundations were made of wood piles, ancient Roman, Greek and Middle Eastern societies already had developed an early variation of concrete.

Types

• The construction industry distinguishes between deep and shallow foundations. Deep foundations are laid more than 3 yards below the surface, often due to poor soil quality or heavy structures. Shallow foundations are laid less than 3 yards below ground and are suitable only when the surface soil is strong enough to support the load.

Materials

• Most foundations are made of concrete, either solid concrete poured into forms onsite or concrete blocks. An alternative is insulating concrete forms (ICFs) made of polystyrene foam.