Intumescent fire protective sheaths useful for the protection of electric cables and conduits from open flame damage and methods for making such sheaths. The sheath comprises sheets of substantially inorganic intumescent material capable of arrangement around the cable or the conduit to form a protective layer. The layer is restrained to expand only in the general direction of the electrical cables or conduits upon exposure to open flames. In the unexpanded state, the sheaths dissipate cable-generated heat due to their higher value of thermal conductivity, their relative thinness and their fin-like shape.
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