Pier-and-beam foundations are wood set on concrete piers. They can be used in any part of the United States for decks, but they also are used in lieu of a basement in some U.S. regions. Several options apply to pier-and-beam foundations.
The beams in a pier-and-beam foundation should be made from strong timber that is pressure treated to withstand weather. The piers, however, can be made of poured concrete, concrete block or clay bricks. Poured concrete and concrete blocks are more appropriate than clay bricks for home construction because they can hold more weight. Clay bricks can be used in deck construction. In some cases, such as a shed and other small buildings, using brick on top of concrete may be advantageous because the concrete offers a solid foundation and the brick is an inexpensive way to build the rest of the pier. The weight of a building determines which building material is best.
The height of the piers depends on the building's design and the location's zoning laws. If you live in a flood zone, then building codes will dictate the piers' minimum height. If no zoning regulations apply to piers, then they can be whatever height you like. Discuss your plans with an engineer to determine the piers' maximum height to still distribute the building's weight safely. Then plan construction using the pier height that best suits that and other specifications.
Reinforcing poured concrete piers with 1/2-inch thick metal rebar is an option. Some building codes require rebar to be placed in concrete piers. A grid of reinforcing rebar adds strength to piers and stability to the structure.
When installing piers for a pier-and-beam foundation, you have options as to how far apart the piers can be installed. Pier placement depends on wall structure and how the weight of the building will be distributed throughout the foundation. Common pier placement distances are 8 to 10 feet apart.