Here, we uncover the robustness of the Z2 topological phases of photonic platforms invariant under the action of parity, time-reversal, and duality (PTD) operators to non-Hermitian effects, e.g., to material dissipation. In particular, it is shown that non-Hermitian PD-symmetric and reciprocal photonic insulators may be split into two classes of topologically inequivalent materials, whose interfaces may support spin-polarized states. To illustrate our theory, we study in detail how the non-Hermiticity may sculpt the topology of a PTD-symmetric parallel-plate waveguide. We find a critical level for the plates loss that separates two different topological phases, identify the phases by their spin Chern numbers and analyze the transition.