This work investigated water diffusion in composites consisting of a permeable matrix reinforced with aligned, impermeable, triangular elements. The triangular elements are expected to induce single axis-, filler orientation-dependent transport behaviour in the composite. Such property is suggested to be useful in slow barrier applications and fast drying processes. To test this idea experimentally, triangular bar-reinforced composite specimens are prepared using thermosetting plastics as representative components. Using water as model diffusant, specimens undergo absorption-desorption-reabsorption gravimetric experiments at 80oC. It is observed that diffusivity decreases when the base side of the reinforced triangular bars is exposed to diffusion and increases when it is the sloped side. Diffusion is also reduced when the triangular bars are in staggered alignment.