We describe a model problem of water transport and phase change in a finite porous layer, which is of interest to our PEM fuel cell modelling group. The singular, degenerate nature of the mathematical model results in an indeterminate form for the interface velocity. In this talk, I will present a front capturing method which avoids the need for explicit implementation of this velocity. The method is shown to accurately capture the interface location, by way of an exact similarity solution and numerical convergence study for a model problem. I will present some computational results and discuss further direction for this work.