To prevent blocking when stored in a superimposed state for a long period of time or at high temperature and in high humidity by laminating a sheet-like surface material having a resin film layer on at least one surface of a damping sound-insulation layer consisting mainly of a high specific gravity filler, a resin component, a rubber component or an asphalt component.

The damping sound-insulation material is manufactured as follows, a water slurry 3 is prepared by supplying an emulsion of a high specific gravity filler and unvulcanized rubber in a tank 2a. The aqueous slurry 3 is transported from the tank 2b through pipe conduits so as to be supplied in a pipe line mixer 7 by separately transporting urethane prepolymer 4 from the tank 2b through pipe conduits. Next, a mixed slurry of the slurry 3 and urethane propolymer 4 is supplied to an applicator bath 11 to subsequently by applied on the sheet-like surface material 1. The mixed slurry applied on the sheet-like surface material 1 is superimposed with another sheet-like surface material 2.