Posted: 25/01/2016 at 20:46
You could be right Zoomer. The guttering on mine is built-in to the sections which run the length of each side at the point the roof meets the sides. It has plastic end-stops which have a connection for a bit of hosepipe to take the rain into a butt.
As for leaks etc, clear silicone sealant cures all manner of leaks and ill-fitting parts on aluminium greenhouses.
Without dismantling the GH, one solution would be to fit U-shaped guttering as close to and slightly below the sections mentioned previously and then run a length of aluminium tape to make sure the water flows down the roof and into the guttering. You'd need to stick the aluminium tape on during a dry period or it will fail to stick properly though.