Proper Method of Constructing a Pier Foundation

Appropriate Area

• Not all areas allow for a home or even a deck to be built safely over a pier foundation. If earthquakes, flooding or hurricane force winds are a concern in your area, consider a different type of foundation, recommends the website Dare to Prepare. All three of these natural occurrences will shift a building over piers and cause serious damage. Soil that is very loose and over-saturated with water won't allow for a stable pier installation either.

Spot Vs. Continuous

• The footing is the concrete base of the pier that is buried underground and supports the weight of the structure. To properly construct a pier foundation, you'll need to consult an engineer to determine if your planned structure requires a continuous buried footer around the perimeter of the building, or if free-standing spot piers at regular intervals will work. Decks and sheds are small enough to use spot footings but larger buildings need a professional consultation.

Choosing Posts

• In each concrete footing, a post must be mounted to build your floor framing on. These posts can be made from wood, metal or concrete. Concrete is the strongest but requires either heavy equipment to position pre-cast pillars or forms for on-site pouring. Metal and wood posts should be adequate for homes and smaller structures if they are large enough to support the weight and appropriately space. Wood posts should not be installed where any part of them will be underground or touching the ground, even if you use pressure-treated wood, if you are making a foundation for a structure instead of a deck.

Proper Spacing

• When designing a pier foundation, plan to have a pier supporting every framing beam of the floor. Adding piers in the center of the structure instead of just around the perimeter prevents the floor of the house from sloping or caving in. Piers need to be added every 8 to 12 feet, depending on the design of the structure. Skipping interior piers without adding some kind of compensation will lead to a dangerous foundation failure.