For the surface protection of construction made up of varying materials rubber lining has proven itself over the decades. For rubber lining on site vulcanized rubber sheets are used. The vulcanization is carried out in an autoclave with the rubber sheeting being in roll form. The autoclave cycle must be carried out so that throughout the entire roll, identical vulcanization conditions occur. For the testing of the vulcanization process and She conformity of the rubber sheet many mechanical tests such as hardness, tensile strength and elongation at break, as well as determination of the crosslink density and the water absorption when immersed in deionized water at raised temperature are suitable. It has been shown through modification of the vulcanization process that the mechanical properties of the rubber sheeting can be improved.