  Motivated by the high sensitivity to Fermi surface topology and scattering
mechanisms in magneto-thermoelectric transport, we have measured the
thermopower and Nernst effect on the (011)-plane of the proposed topological
Kondo insulator SmB$_6$. These experiments, together with electrical
resistivity and Hall effect measurements, demonstrate that the (011)-plane also
harbors a metallic surface with the effective mass in the order of 10-10$^2$
$m_0$. The surface and bulk conductances are well distinguished in these
measurements and are categorized into metallic and non-degenerate
semiconducting regimes, respectively. Electronic correlations play an important
role in enhancing scattering and also contribute to the heavy surface state.
