<p>Compared to monolithic glass, laminated glass (LG) offers structural advantages in impact resistance and shard scatter prevention, leading to a significant increase in its demand for modern building applications. However, there is still a lack of comprehensive understanding of the thermal behaviour of laminated glass, especially its vulnerability to ignition, a critical aspect that is often overlooked and requires further investigation. In this study, laminated glass composed of two annealed glass panes with an interlayer of polyvinyl butyral (PVB) film, 18 experiments were conducted by varying both the glass thickness and the PVB thickness under a uniform radiant heat flux of 45&#xa0;kW/m². Results indicated that PVB ignited from sample edges or through cracks of the glass panels, indicating that cracks served as a channel for flame propagation, thus accelerating PVB ignition. Increasing glass thickness prolonged the breakage time of both panels. The average breakage times for 4mm, 6 mm, and 8 mm glass were 61 s, 59 s, and 94 s for radiation-exposed panels (Pane 1), and 176 s, 197 s, and 394 s for ambient-exposed panels (Pane 2), respectively. For ambient-exposed panels, the 8 mm glass took over twice as long to break as the 4 mm glass. An increase in PVB thickness resulted in longer total crack lengths on two glass panels after the experiment. The results represent a 24.8% reduction in crack length (Pane 1) from 4 to 8&#xa0;mm glass. Furthermore, when the glass panel fell out, the Heat Release Rate Per Unit Area (HRRPUA) exhibited a marked surge, resulting in multiple HRRPUA peaks and an elevated fire risk. By contrast, samples with intact glass panels typically exhibited a single HRRPUA peak. These experimental findings provide critical insights into the thermal behaviour of structural laminated glass under fire exposure conditions, establishing a foundational framework for performance prediction and safety assessments.</p>