Field Evaluation: Quadrant Homes and Woodinville Lumber
Project Summary
Evaluation of the Perforated Shear Wall Design Method Applied in Panelized Construction
An advanced lateral design method and an innovative use of metal connector plates were used in the design of a new home in Washington (a high seismic risk region) to demonstrate potential cost savings while maintaining lateral strength requirements. The Research Center worked with local builder, Quadrant Homes, and its panel manufacturer, Woodinville Lumber, to construct a home using pre-engineered wall panels that had been designed using the perforated shear wall method. This design method, together with the use of integrated metal connector plates, is expected to save labor and material costs in the erection phase of construction, while only slightly increasing panel production costs.
First, the original wall panel designs were re-engineered using the widely recognized and tested perforated shear wall design method. This resulted in a reduction in the number of tie-down connections required. Then, metal truss connector plates were incorporated into the design to enable the use of rod-and-bracket connectors instead of the typical exterior straps. The connector plates were located at the corners of the wall panels near the rod-and-bracket connections. The plates provided a continuous load path from the top plate of the wall to the end stud without relying on the end nails in the stud. This allowed workers to install connection hardware from inside the building rather than on a ladder on the exterior of the building.
To evaluate this new technology, two houses with the same plan were constructed and compared. One house incorporated the advanced lateral design method with metal connector plate enhancements, while the other used the traditional segmented shear wall design method and strap connections. The NAHB Research Center monitored the manufacture and installation of the wall panels and hardware on each house. Particular attention was given to the application of the metal connector plates in the manufacturing process and to the installation of the tie-down hardware in the field.
