The Attic Notebook

When rain falls heavily, a properly functioning gutter system channels water away from the roof and foundation. An overflowing gutter does the opposite, dumping water where it can cause damage. The direct answer is that gutters overflow because something blocks or restricts the flow of water through the channel, the downspout, or both. The blockage can be debris, a sagging section, a misaligned joint, or simply a system that was undersized for the roof it serves. Understand