This paper investigates the effect of brick dust on the water-releasing properties and dewatering of hydrated lime mortars. Dewatering in masonry occurs when freshly mixed mortar is applied to a dry substrate (e.g. fired bricks, stone) and can influence the physical and mechanical properties of the mortar and the mortar-masonry bond. Controlling these properties provides an important opportunity to optimise performance. This study evaluates the water transport kinetics of hydrated lime-brick dust mortars. The study demonstrates that the particle size distribution of the brick dust can effectively control transfer sorptivity and dewatering time. The measured dewatering times correlated to theoretically calculated values demonstrating the ability to accurately predict the dewatering characteristics of a mortar from a knowledge of the mix design. The use of waste brick dust in hydrated lime mortars provides an environmentally friendly alternative to waste disposal by routes such as landfill.