Abstract: During manufacture of a sewer or tunnel lining section, sand-resin material is deposited over a mould, to define a central part of the section. Sand-resin material is removed using a wire arranged to lie a predetermined radial distance from the surface of the mould. The wire is passed around the surface of the sand-resin layer whilst maintaining the predetermined radial distance, the predetermined radial distance comprising, or being slightly greater than a preset minimum thickness. The use of a wire to remove excess sand-resin material has been found to be particularly effective, and surprisingly the excess material does not re-adhere to the underlying surface after the wire has passed. This is despite the required tackiness of the sand-resin mixture.