The $\ensuremath{\beta}$-decay properties of very neutron rich nuclei $^{86}\mathrm{Ge}$ and $^{86}\mathrm{As}$ were measured at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. Spectroscopic information on new excited states in $^{86}\mathrm{As}$ and in $^{86}\mathrm{Se}$ was obtained and is interpreted within an advanced shell model approach. These calculations, previously explaining well the structure of $^{84}\mathrm{Ge}$ and $^{85}\mathrm{Ge}$, are not able to reproduce all the experimentally determined features of the measured level schemes of $^{86}\mathrm{As}$ and $^{86}\mathrm{Se}$. The Gamow-Teller decay of $^{86}\mathrm{Ge}$ and $^{86}\mathrm{As}$ is also investigated in a shell-model framework. The fission yield for $^{86}\mathrm{Ge}$ is discussed.