Subsection 1809.10 - Pier and curtain wall foundations Except in Seismic Design Categories D, E and F, pier and curtain wall foundations shall be permitted to be used to support light-frame construction not more than two stories abovegrade plane, provided the following requirements are met:
1. All load-bearing walls shall be placed on continuous concrete footings bonded integrally with the exterior wall footings.2. The minimum actual thickness of a load-bearing masonry wall shall not be less than 4 inches (102 mm) nominal or 35/8 inches (92 mm) actual thickness, and shall be bonded integrally with piers spaced 6 feet (1829 mm) on center (o.c.).3. Piers shall be constructed in accordance with Chapter 21 and the following: 3.1. The unsupported height of the masonry piers shall not exceed 10 times their least dimension.3.2. Where structural clay tile or hollow concrete masonry units are used for piers supporting beams and girders, the cellular spaces shall be filled solidly with concrete or Type M or S mortar. Exception: Unfilled hollow piers shall be permitted where the unsupported height of the pier is not more than four times its least dimension.
3.3. Hollow piers shall be capped with 4 inches (102 mm) of solid masonry or concrete or the cavities of the top course shall be filled with concrete or grout.4. The maximum height of a 4-inch (102 mm) load-bearing masonry foundation wall supporting wood frame walls and floors shall not be more than 4 feet (1219 mm) in height.5. The unbalanced fill for 4-inch (102 mm) foundation walls shall not exceed 24 inches (610 mm) for solid masonry, nor 12 inches (305 mm) for hollow masonry.