The prescriptive solutions specified in the following sections shall not be permitted to be used in the following conditions:
Roof attachment shall be accomplished with minimum 8d nails as follows:
Exception: 2 × 3 intermediate blocking can be eliminated provided all sheathing is 5/8-inch nominal tongue and groove structural panels.
Ridge straps 11/4 inches × 20 gage shall be attached to each pair of opposing rafters with five 8d nails at each end into the framing member.
Wall sheathing shall be a minimum 7/16-inch structural panel. Nailing shall be in accordance with Table R602.3 (1) and the following:
A 4-foot segment of wall sheathing shall be designated as a shear wall at each corner of the structure at each floor, and no more than 24 feet apart along a wall length. The following additional requirements apply:
First-story shear walls shall be connected to the foundation below with connection anchoring capable of 3,500-pound hold-down capacity, in addition to conventional foundation anchor bolt requirements in the remainder of the panel. The hold downs shall be fastened to each end of the shear wall at the double stud.
Anchor bolts shall be installed in accordance with Section R403.1.6 and the following:
|1- & 2-story buildings||1/2" @ 48" o.c. or||5/8" @ 72" o.c.|
|3-story building||1/2" @ 24" o.c. or||5/8" @ 36" o.c.|
Alternate: Prefabricated and pre-engineered connections in design and quantity sufficient to equal strength of anchor bolt specification above.
Exception. See Exception 2 to AA203.2.1.
For Wind Zones 2 (110 mph) and 3 (120 mph) the following conditions apply:
Exterior bearing and nonbearing walls greater than 10 feet in height shall be 2 × 6 @ 16 inches o.c. minimum.
Walls with a total height greater than 10 feet shall be permitted to use 2 × 4 @ 16 inches o.c. providing the wall is limited to 10 feet in length and the individual studs are not greater than 9 feet in length.