I have a K2 Ogee gutter that spans across approximately 7meters and has a joint. The problem is that the joint is forever dripping water. From what I understand the rubber gaskets in the joint is supposed to be able to sufficiently seal it from water leaking out. I bought a new gutter joint to replace the old one and bought a 2 extra clips so that the gutter has enough support on both sides of the joint. The joint looks like the one pictured below. I took off the old joint, there is a gap between the two pieces of gutter of about 7-10mm which I assume is normal for expansion. Problem is i've fitted the new joint, and its much more tighter than before because i fitted supporting clips on both sides but it still doesn't full seal it, the water gets underneath the gaps of the two pipes and eventually leaks out. My theory is that the rubber gasket isn't getting compressed enough to create the tight seal. Any ideas what else I can try? I could put gutter sealing from the top to prevent water getting under the pipes and onto the joint but then that will close up the expansion gap etc.