I am replacing my guttering which was brought down by snow sliding off the roof. I am using Marley 110mm half-round plastic with plastic clips. The problem is that the clips keeps breaking when I snap them on to the gutter - about one in every three goes this way. I assume I am doing it the right way, i.e. fitting the back of the gutter in to the back of the clip and then pushing the front of the clip to snap it over the front edge of the gutter. The only thing I can think of is that the clips may be brittle in cold weather. It was about 6C today. Either that or they are faulty.
It's not so much the cost, about 60p each, just a damned nuisance as you need to undo the gutter to replace the broken clip.