A device and a method allow for adhering sealing tape to open end of a multilayer sheet, usable at the production line and at the installation site. The device comprise means for applying pressure and heat onto the sealing tape and cutting blades for removing protruding edges of the sealing tape after it was adhered. The method comprise providing of a sealing tape, attaching and adhering the sealing tape to an open end of a multi-wall sheet by means of heat and/or pressure and adhesive and removal of protruding edges using cutting blades.