A hybrid ceramic structure and a method for protecting the hybrid ceramic structure from moisture attack in a high temperature combustion environment are provided. The structure includes a ceramic matrix composite (CMC) substrate (12). A thermal insulation material (14) is disposed on the substrate. A vapor resistant material (20) is applied through at least one surface of the hybrid ceramic structure while the hybrid ceramic structure is in a bisque condition that provides a degree of porosity to the hybrid ceramic structure so that the vapor resistant material is infiltrated through interstices available within a thickness of the hybrid ceramic structure.