Had news eavestroughs put up awhile ago, and the installer seems to have done a bad job. In a heavy rain they overflow at the ends opposite the downspout, and there's standing water in them after the rain. I'm getting the contractors to come back and rehang them, but in the meantime I wonder if I need an additional downspout. The roof of my house, in side profile, is shaped like this:
(back) (front) /\ / \ / \ ____________/ \__ |------------