Novel aluminised E-glass fibre reinforced unsaturated polyester composites, originally formulated for enhanced thermal and electrical shielding properties were evaluated in terms of their water absorption. One of the major obstacles delaying the acceptance of novel composites in engineering applications is the degradation of the polymer matrix material by moisture, which effects the physical and mechanical performance over time. The objective of this study was to characterise and quantify the degree of water absorption of novel aluminised E-glass reinforced unsaturated polyester composites. Aluminised E-glass composites were compared alongside their unmetallised E-glass counterparts. Two sets of temperature were used for this study. Results show that aluminised E-glass significantly reduces the saturation point compared to unmetallised E-glass. The differences between aluminised and unmetallised are correlated to fibre coatings. At elevated temperatures the aluminised E-glass sample is unstable and exhibits significantly higher water absorption indicating that a new failure mechanism is occurring.