Pan, valve, plunger, offset, washout, latrine, frost proof and other water closets having a concealed trap seal or an unventilated space or having walls that are not thoroughly washed at each discharge shall be prohibited. Any water closet that permits siphonage of the contents of the bowl back into the tank shall be prohibited. Trough urinals shall be prohibited. A fixed wooden wash tray or wooden sink shall not be installed or maintained in any building designed or used for human habitation. No metal lined wooden bathtub shall be installed or reconnected.