The noisy downpipe nightmare why and a right repair

How to stop noisy downpipes?
Lots of people are driven mad by that noisy downpipe that goes 'ting!' in the middle of the night. This is the nightmare downpipe.
There are also lots of suggestions to fix this noisy downpipe problem.
When we were asked to eliminate the noisy downpipe nightmare recently, we did some investigation work and came up with what we think is the RIGHT way to stop the noisy downpipe problem....