A pier foundation, sometimes called a post-and-beam or pier-and-beam foundation, consists of wood posts or concrete piers set into the ground to bear the weight of a building or home. Pier foundations are easier to build and are less costly than the more common concrete foundation. They are best used for smaller buildings and homes with a low likelihood of earthquake or hurricane force winds.
A pier foundation lifts a house up off the ground so that the building is separated from the soil. Because there is little direct contact with the ground, moisture and termites are less of a problem than with other foundations. Piers themselves are made of concrete, masonry or insect-resistant wood. Pier foundations are unlike conventional concrete foundations in that they support structural loads at a number of distinct points. Some pier foundations are as simple as concrete-filled cardboard tubes dropped into hand-dug holes. Complex pier foundations incorporate very deep piers that can support extremely heavy loads.
Some builders believe that pier foundations are environmentally friendly because they require less excavation and soil disruption than other types of foundations. All foundations can have problems in wet clay soils, especially when they freeze. However, this is especially true of pier-and-beam foundations where differential settlement can cause alignment problems. In solid soil, a pier foundation can provide a stable and long-lasting structural foundation. Pier foundations are often used for homes on a hillside or near a large body of water such as a lake, river or beach.