Regular and irregular hexahedral grids are a common geometric primitive used to represent spatial property distributions. It is often required to calculate closed isosurfaces based on these given spatial properties for visualisation and computation purposes. This talk aims to introduce an efficient method for generating multiple surfaces from a given hexahedral grid. First, it will provide an overview of the structure of different kinds of hexahedral grids, such as regular voxet-based grids and irregular stratigraphic grids. Subsequently, we will present a performant algorithm to generate multiple closed isosurfaces at once for a given hexahedral grid with a specific property and a set of isovalues. Finally we will discuss real-world use-cases and performance numbers.