Title: Examination of Lateral Stiffness and Strength of Pitched Residential Roof Diaphragms with Implications for Seismic Design

There are about 80 million single-family dwellings (SFD) in the United States, predominantly of wood-frame construction. Of these, 68 % are owner occupied. A home is typically the largest single investment of a family, and is often not covered by earthquake insurance, even where it is available. Of all SFD in America, 50 % were built before 1974, and 76 % built before 1990. Most wood frame SFD (WFSFD) were built to prescriptive code provisions before seismic requirements were introduced. This dissertation examines a broad field of seismic research applicable to WFSFD seismic analysis and the design, and to the retrofit of existing WFSFD. It summarizes the “state-of-the-art ” of seismic experimentation and seismic evaluation, and provides observations and recommendations for future research. The study showed that performance based design (PBD) needs to develop a consensus on performance objectives for WDSFD with respect to damage and repair costs, including new design techniques which balance life-safety with the effects of damage to building finish materials. There is also a strong need to develop a better understanding of the effects of WDSFD components, attachment, the lateral force resisting system and how loads ar