A method for treating a surface of a porous material in an environment is provided, comprising setting the temperature of the surface to a value T1 and setting the pressure of the environment to a value P1, contacting the surface with a fluid having a solidifying temperature at the pressure value P1 above the value T1 and having a vaporizing temperature at the pressure value P1 below 80° C., thereby solidifying the fluid in pores of the material, thereby sealing the pores, treating the surface, wherein the treatment is preferably an etching or a modification of the surface, and setting the temperature of the surface to a value T2 and setting the pressure of the environment to a value P2 in such a way as to vaporize the fluid.