[BS] A206.3 Development of Anchor Loads Into the Diaphragm
Development of anchor loads into roof and floor diaphragms shall comply with Section 1613 of the California Building Code using horizontal forces that are 75 percent of those used for new construction.
In wood diaphragms, anchorage shall not be accomplished by use of toenails or nails subject to withdrawal. Wood ledgers, top plates or framing shall not be used in cross-grain bending or cross-grain tension. The continuous ties required in Section 1613 of the California Building Code shall be in addition to the diaphragm sheathing.
Lengths of development of anchor loads in wood diaphragms shall be based on existing field nailing of the sheathing unless existing edge nailing is positively identified on the original construction plans or at the site.
Exception: If continuously tied girders are present, the maximum spacing of the continuity ties is the greater of the girder spacing or 24 feet (7315 mm).