Water impervious heat shrinkable tube

A water impervious heat recoverable rubber or plastic comprising:

• an inner and outer layer forming a tube, each layer having a thickness in the radial direction of the tube and each layer comprising a heat shrinkable plastic or rubber selected from the group consisting of polyethylene, polyvinyl chloride, saturated polyester, cross-linked polyethylene, ethylene-propylene rubber, silicone rubber, chloroprene rubber, and fluoroplastic;
• a laminated foil layer interposed between said inner and outer layers, the thickness of the inner layer being less than the thickness of the outer layer over the complete extent of the portion of the tube containing said laminated foil layer, said laminated foil layer having two longitudinal edges and comprising a metal foil film having a thickness of 0.01 mm to 0.1 mm and being selected from the group consisting of a copper foil film, an aluminum foil film and a lead foil film, and an electrically insulating or semiconducting rubber or plastic sheet laminated on each surface of said metal foil film, wherein the rubber or plastic is selected from the group consisting of high density polyethylene, medium density polyethylene, low density polyethylene, polypropylene polybutene-1, polymethylpentene, an ethylene-ethylacrylate copolymer, an ethylenevinylacetate-vinyl chloride graft copolymer, chlorinated polyethylene, isoprene rubber, chloroprene rubber and styrene-butadiene rubber, said laminated metal foil layer extending up to the entire length of said tube and extending within said tube over more than 360.degree. in the circumferential direction, the complete longitudinal extent of the two longitudinal edges of said laminated metal foil layer overlapping each other in said circumferential direction over a predetermined distance in said circumferential direction.