I've got a leaky gutter. When I got up to the roof and looked, the problem is a join between two different sizes of guttering at the boundary between my house and next door. Why they're different sizes is an utter mystery to me. I seem to have 112mm half round and I THINK the stuff next door is 150mm with notches at the ends of the pipe. There's an adaptor, and the leak is because the length of 112mm on my side is about half an inch too short and doesn't quite engage in the adaptor. I don't see a huge problem with replacing the length of guttering with one a bit longer and I may even take the opportunity to replace the lot--it's only about 6m and a couple of bends.
But to be thorough about it I'd like to replace the 112m--150mm adaptor as well, and here's the problem. I haven't been able to find one. Any advice on who might stock a diameter reducing union?