PREFAB SHEAR WALLS In my 30 years of framing houses on the West Coast, I've seen a steady rise in the use of techniques and materials designed to resist the powerful lateral forces imposed by earthquakes — "shear" forces, as most West Coast carpenters call them. When I first started framing in Southern California, we simply used let-in 1x6 braces and 1/2-inch-diameter foundation anchor bolts 4 feet on-center. By the end of the '70s, let-in bracing began to give way to small amounts of shear-nailed plywood. By the mid-1980s, exterior shear-ply completely covered exterior frames, and, for good measure, a few hold-down brackets were tossed into the mix. But none of this compares to the
