SEARCHING FOR THE FACTOR OF SAFETY: A STUDY OF WOOD ROOF SYSTEM CAPACITY AS IT APPLIES TO SOLAR PHOTOVOLTAIC INSTALLATION

The recent drive to install residential installation of photovoltaic roof systems has generated the need to re-examine the structural capacity of residential structures. Currently, a perspective exists that residential wood roofs may not be able to carry the additional load of a photovoltaic (PV) array. This research seeks to address how the addition of PV installations can affect the structural capacity of residential wood roof systems and to investigate the current methods in which roof systems are assigned their working strengths. With the goal of finding ultimate capacities of wood roof systems, empirical tests were conducted in a laboratory setting and results were compared with current building and design codes. These comparisons help to identify factors of safety and other assumptions that exist in current building codes and therefore elicit a better understanding of the structural capacity of wood roof systems. Finally, a computer analysis was conducted to better understand the way in which a PV installation affects the structural performance of wood roof systems