1809.5.5 Timber footings.

Refer to Chapter 23.

1809.5.6 Wood foundations.

Refer to Chapter 23.

1809.5.7 Pier foundations.

The design, materials, and construction of pier foundations shall conform to the requirements of Sections 1809.5.2, 1809.5.3, and 1809.5.7.1 through 1809.5.7.6.

   Exception: Piers shall be load tested as a deep foundation in accordance with the applicable portions of Section 1810 when the bearing stratum is not physically available for inspection during construction as required by Chapter 17.

1809.5.7.1 Dimensions and height.

The minimum horizontal dimension of piers shall be 2 feet (609.6 mm), and the height shall not exceed 12 times the least horizontal dimension.

1809.5.7.2 Concrete design.

Where adequate lateral support is furnished by the surrounding materials defined in Section 1810.7 of this code, piers may be constructed of plain or reinforced concrete and the requirements of ACI 318 shall apply.

   Exception: Where adequate lateral support is not provided, and the ratio of unsupported height to least horizontal dimension does not exceed three, piers of plain concrete shall be designed and constructed as pedestals in accordance with ACI 318. Where the unsupported height to least horizontal dimension exceeds three, piers shall be constructed of reinforced concrete, and shall conform to the requirements for columns in ACI 318.

1809.5.7.3 Reinforcement placement.

Reinforcement shall be tied and placed as a unit in the pier prior to placement of concrete.

Exception: Steel dowels embedded 5 feet (1524 mm) or less in the pier may be placed individually. Reinforcement is permitted to be wet set and the concrete cover that is otherwise required to measure a minimum of 2 1/2 inches (63.5 mm) may be reduced to 2 inches (50.8 mm) for Groups R-3 and U occupancies not exceeding two stories of light-frame construction, provided the construction method is approved by the commissioner.