In last month's column, I looked at some common problems with the installation of shear wall hold-downs. This month's column looks at issues related to nailing off the structural panels that carry the shear forces in a shear wall. Tests done at the American Plywood Association have shown that nailing is the controlling factor in shear wall performance. Shear walls fail in one of three ways: the nails bend, the plywood (or OSB) buckles and pulls through the nail head or pulls out the nail, or the framing lumber fails. The lumber failure — typically splitting — is also a result of nailing. The lumber splits either because the nails are placed too close to the edge, or
