This study investigates the mechanical propertiesMechanical property of a new composite materialComposite material consistingCharacterization of castor oil-based polyurethaneCastor oil-based polyurethane resin reinforced with linearly arranged fique fibersFique fiber. The main objective is to develop a material with high flexural strengthFlexural strength and toughnessToughness, making it suitable for construction applications. These properties are especially relevant for construction applications in humid environments and at high temperatures. To evaluate the durability and resistance of the compositeComposite to adverse conditions, an accelerated aging test was performed in a controlled chamber. Hardness measurements were taken before and after the aging process to evaluate the behavior of the material under simulated environmental stress. The results of this study provide information on the potential of this composite materialComposite material for construction applications with an interesting possibility of being used as thermal insulation in roofs, highlighting its mechanical strength and its resistance to adverse environments.