Five-Story Multi-Family Building Continuous Anchor Tie-Down System

Figure 1-The rods are continuous from foundation to roof, and are seen here anchoring the ends of the shear walls on each side of a window.

Framing of a five-story, wood-framed apartment building is Nashua is nearly complete. Lately the framers have been installing the continuous anchor tie-down system. The wind and seismic loads on this building were too high for traditional wood shear wall hold-downs, so we utilized a system that continuously connects the shear walls on each floor and is anchored to the concrete foundations. (The more expensive alternative was steel braced frames or steel moment frames.) We chose Simpson Strong-Tie’s Strong-Rod Simpson, and Simpson custom-designed their proprietary components including the rods, couplers, and take-up devices. The high uplift forces dictated the concrete foundation size at most anchorage locations!

Figure 2-Anchor rods for shear walls meeting at an exterior corner, with the bottom plate take-up devices