At the moment I am having new fascias and gutters fitted and have noticed the fitters have put screws into the drainpipe securing the different sections together, is this the right method or should the sections simply slot together being held securely by the drainpipe clips?

You mean downspouts... yes they are typically held together using a screw or two on each section.

Thanks smoothy, just looks awful with black plastics and shiny screws stuck in them ! Always thought you shouldn't have any potential exits for water apart from the outlet. Thanks again.

Surprising enough, those screws are self tapping and thus fit very tightly. You won't get leaks from them. One or two were sufficient at each joint... they slip fit but this keeps them together. Better installers use color matched screws. But from a distance you barely even notice them.

Thanks again Smoothy, feel a lot better now.