  In this contribution we prove the existence of weak solutions to degenerate
parabolic systems arising from the coupled moisture movement, transport of
dissolved species and heat transfer through partially saturated porous
materials. Physically motivated mixed Dirichlet-Neumann boundary conditions and
initial conditions are considered. Existence of a global weak solution of the
problem is proved by means of semidiscretization in time and by passing to the
limit from discrete approximations. Degeneration occurs in the nonlinear
transport coefficients which are not assumed to be bounded below and above by
positive constants. Degeneracies in all transport coefficients are overcome by
proving suitable a-priori $L^{\infty}$-estimates for the approximations of
primary unknowns of the system.
