To provide a method for efficiently manufacturing a hydraulic laminate obtained by laminating a norbornene resin layer excellent in acid resistance and alkali resistance on the surface of a hydraulic composition molded object, and a surface protecting method for the hydraulic composition molded object.

The hydraulic laminate has the hydraulic composition molded object and a norbornence resin layer formed by the bulk polymerization of a norbornene type monomer on the surface of the hydraulic composition molded object in the presence of a metal carben complex during the uncuring of the molded object. The manufacturing method of the laminate has a process for coating the surface of the the uncured hydraulic composition molded object with a reaction solution, which is obtained by mixing the monomer liquid containing the norbornene monomer with a catalyst solution containing the metal carben complex to form the norbornene type resin layer. The norbornene type resin layer is formed on the surface of the hydraulic composition molded object by coating the surface of the uncured hydraulic composition molded object with the reaction solution.