Ultra High Performance Fiber Reinforced Concretes (UHPFRC) present outstanding mechanical properties and a very low permeability. Those characteristics make them very attractive for the rehabilitation of existing structures and the conception of new structures. To define the range of admissible tensile deformation in those materials, the influence of imposed tensile deformation and subsequent cracking on permeability and absorption was studied. The transport properties of water and glycol were assessed in order to estimate the effect of the interaction of water with a specific UHPFRC. The experimental results demonstrate that permeability and absorption increase steadily until a residual tensile deformation of 0.13% is reached in the material, then water seeping rises distinctly. During experiments, the interaction of water with the UHPFRC decreases by 1 to 3 orders of magnitude the permeability and reduces absorption by approximately 50 to 85%. Test results reveal the high capability of the material to seal cracks and improve its water-tightness with time.