A method and apparatus for moulding a fluid settable material. The apparatus includes male and female mould halves defining between them a mould cavity having an inlet thereto for the introduction of a fluid settable material; between the male and female mould halves of the cavity a seal can be interposed to seal the mould cavity from the atmosphere. At least one vacuum outlet from a mould half leads via an isolation valve to a vacuum source. The method includes the steps of creating a depression in the mould cavity by withdrawing air therefrom through the vacuum outlet via the isolation valve, introducing a fluid settable material into the thus evacuated mould cavity until the mould cavity is wholly filled by the settable material, closing the isolation valve between the vacuum outlet and the vacuum source, injecting a small additional quantity of fluid settable material under pressure into the mould cavity, closing the inlet through which the fluid material is introduced into the mould cavity and allowing the fluid settable material to solidify.