A method for applying film to a structure comprises presenting a film from a roll 5 across two spaced apart channels 11 with a film overlap either side of the channel and forcing the overlap into the channel by means of downward pressure on a former 6 on a profile element 10 thereby tensioning the film. The former being rotatable in a direction of the film coming off the roll. The machine comprises a bridge 2, legs which having mountings with the roll and are associated with the channel. Also disclosed is a method and machine for localized heating of the film to provide the required tension. The film may be ETFE (ethylene tetrafluoroethylene) and the structure may be a greenhouse or polytunnel
