(A) General. Cavity wall masonry is that type of construction made with brick, structural clay tile or concrete masonry units or any combination of such units in which facing and backing are completely separated except for the metal ties which serve as bonding.
(B) Construction.
(1) (a) In cavity walls neither the facing nor the backing shall be less than four inches in thickness and the cavity shall be not less than one inch net in width nor more than four inches in width. The backing shall be at least as thick as the facing.
(b) Exception: where both the facing and backing are constructed with clay or shale brick, the facing and backing may be three inches in thickness.
(2) The facing and backing of cavity walls shall be bonded with three-sixteenths inch diameter steel rods or metal ties of equivalent strength and stiffness embedded in the horizontal joints. There shall be one metal tie for not more than each four and one-half square feet of wall area for cavity widths up to three and one-half inches net in width. Where the cavity exceeds three and one-half inches net in width, there shall be one metal tie for not more than three square feet of wall area. Ties in alternate courses shall be staggered and the maximum vertical distance between ties shall not exceed 24 inches and the maximum horizontal distance shall not exceed 36 inches. Rods bent to rectangular shape shall be used with hollow masonry units laid with the cells vertical; in other walls the ends of ties shall be bent to 90 degree angles to provide hooks not less than two inches long. Additional bonding ties shall be provided at all openings, spaced not more than three feet apart around the perimeter and within 12 inches of the opening. Ties shall be of corrosion-resistant metal, or shall be coated with a corrosion-resistant metal or other approved protective coating.
(Prior Code, § 9-117) (Ord. 94-11B, passed 4-21-1994)