In this work, the single-pass fabrication of more than 1000 μm thick René N5, a high γ′ and "non-weldable" single-crystal superalloy on top of investment cast René N5 substrates having 〈100〉 and 〈001〉 crystallographic orientations through scanning laser epitaxy (SLE) was demonstrated. SLE is a powder-bed fusion based additive manufacturing (AM) process that was exclusively developed to repair and manufacture gas turbine hotsection components made of nickel-base superalloys. The microstructures of the René N5 deposits were investigated using optical imaging, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and electron back scatter diffraction (EBSD). Optical microscopy revealed that the substrate crystallographic orientation of 〈100〉 did not prohibit dendritic growth along the 〈001〉 direction in the deposit region. Scanning electron microscopy investigations showed the presence of finer microstructure in the deposit region compared to the substrate region. The crack-free deposits obtained for René N5 represent one of the few successes reported for a "non-weldable" single-crystal superalloy of its kind using powder-bed based AM process.