Modeling of the fire performance of fiberglass reinforced composite pipe was investigated in this study. A multidimensional heat transfer model was developed and used to capture the essentials of thermal transport and material decomposition. A finite difference modeling (FDM) numerical approach is used in solving the coupled multidimensional Fourier equation with chemical decomposition response model. The fire resistance of a dry hydrocarbon fire test is simulated in this analysis. Transient temperature distributions in the joined section of a composite-to-composite FRP pipe where failure is most likely to occur were predicted for comparison with experimental results. The FRP materials used in the analysis were E-glass and glass-phenolic.