Posted: 17/03/2014 at 15:44
What a fuss your builder is making over this, is he hourly paid!!. maybe he doesn't really know. Did you really need a builder to put a butt in?
The idea of the diverter is to catch the water in the butt, when its full it automatically goes down the drain pipe. Never had a problem.
I have 12 various butts around, some are just big dustbins, anything that catches water. Never had a problem, if something has laid eggs in there they have never been a problems to any of my plants.