By Ethan Davis
Being in the footings and foundations business, I frequently get questions from my friends about what I do. One question people ask is what exactly is a foundation. From the ACI website, it describes foundations as follows:
There are three foundation types:
1. T-shaped: A traditional foundation method to support a structure in an area where the ground freezes. A footing is placed below the frost line and then the walls are added on top. The footing is wider than the wall, providing extra support at the base of the foundation.
2. Slab-on-ground: A slab is a single layer of concrete, several inches thick. The slab is poured thicker at the edges to form an integral footing; reinforcing rods strengthen the thickened edge. The slab normally rests on a bed of crushed gravel to improve drainage.
3. Frost-protected: This foundation relies on the use of two sheets of rigid, polystyrene insulation—one on the outside of the foundation wall and the other laid flat on a bed of gravel at the base of the wall—to prevent freezing, which is a problem with slab-on-ground foundations in areas with frost.
This is a simple overview, but anyone in the business will tell you that it gets a lot more complex for each project.