Thanks again for your reply. The overflow definitely happens away from the downpipe but whether it happens at the downpipe as well I can't say for sure. The property is…

I just found this Stratco document which has some ideas as well.

Thanks to both of you for your detailed and well thought out responses. The Supa Gutter Pumper and mini rainwater head options both sound interesting and more pragmatic than anything…

Thanks for your response and taking an interest.
Yes only the patio area gutters overflow.
Last time I walked around on the roof there was no organic matter in the gutter.…

Hello,
I have a 30 y/o single story brick and tile house in Perth currently rented out. The gutters (~80 lineal meters) are corroded and need to be replaced. Outside the…