Could anyone possibly advise how best to stop a leak where the guttering is joined at a corner (one is a right angle corner, the other is sort of 45deg corner). To further complicate this query, one of the gutters in question is pvc, the other aluminium (not mixed and matched obviously - we're talking two seperate buildings, two seperate leaks here). I thought now might be a good time of year to tackle it as I might have some chance of working on it dry. I did try silicone (? I think that's what I used) on the pvc gutter last year, but no joy. It still allows water to drip out furiously from underneath the gutter corner when it rains, and this is starting to affect the paths below the drip.