Fire statistics suggest that there is an urgent need for improved performance of light-weight truss construction in fire scenarios. This thesis proposes the use of Fire Retardant Treated Wood (FRTW). Several floor truss systems were designed for a residential living room using sawn lumber and FRTW. A finite difference, heat transfer model was used to determine time to collapse and to identify modes of failure during a simulated exposure to the standard ASTM E-119 test fire curve. As part of ongoing research at WPI, this is an initial effort to use analytical methods in the study of heat transfer and structural performance of wood construction during fire conditions. Results were examined for important relationships to further advance the understanding of collapse mechanisms in wood trusses. Experimental procedures for further testing have also been developed. Acknowledgment that in-service conditions may alter structural fire performance is made and the implications are discussed. An alternate fire scenario, more representative of residential fire loading, was also developed and compared to the ASTM E-119 fire curve.