Where a roll brace is not aligned with each guard post, the framing at the edge of the floor shall consist of a minimum 6×10 sawn timber or a minimum 5-1/8 inch x 9-1/4 inch (130mm x 235 mm) structural glued laminated timber and shall be braced to resist rotation by roll bracing as described in Section R502.11.3 at intervals of 48 inches (1219 mm) or less.