This paper presents an investigation into the analytical modelling of the behaviour of unreinforced and fibre-polymer reinforced short-span glulam beams. The research programme evaluated a total of five unreinforced and nine reinforced glulam beams that were tested to failure under four-point bending. The reinforced configurations consisted of two or four layers of simple tension and U-shaped tension FRP reinforcement. A comparison between the experimental and predicted load–displacement curves is presented, highlighting the discrepancies in the experimental and predicted displacement at the maximum load. The impact of the modification factor, αm, in the model was also investigated. The analysis did not use a modification factor as no wood tensile strain enhancement observed due to alternative failures modes such as horizontal shear and simple tension failure at the FRP termination points occurring instead of a flexural failure in the maximum moment region. The effects of FRP development length, the corresponding stress concentrations at the start and end of the FRP reinforcement, and inherent shear strength of the glulam relative to the modification factor, αm, should be considered for future models to accurately predict the appropriate failure mode.