Structural Implications of Increased Panel Use in Wood-Frame Buildings

To improve performance and lower cost, conventional wood-frame construction has evolved to incorporate increasing numbers of manufactured components. Through recent work at the Massachusetts Institute of Technology (MIT) to develop a panelized roof system, other, more general observations have been made about the structural implications of panel use, and these observations form the basis for this paper. A partial exploration of structural response in conventional wood-frame construction is included as background, with a particular emphasis on sheathing. Panelized and modularized buildings represent a significant shift from historical practice, with structural implications for floors, walls, and roofs. Without the structural redundancy and load sharing that continuous envelope sheathing provides, panelized wood-frame buildings require more and careful engineering to achieve performance comparable to conventional construction. Floors, walls, and roofs need panel-to-panel joints that resist differential transverse deflection and possess in-plane shear strength and stiffness comparable to site-build, staggered-sheathed assemblies. Wherever structural response includes diaphragm action, the disruption of sheathing and perimeter-chord continuity both have consequences for panelized building systems.