Overflow is a flow problem. The gutter is receiving water faster than the system can move it through the outlet and downspout.
Start with the easiest causes
- Debris blocking the trough
- A clogged outlet or downspout elbow
- A sag that creates a low spot
- Poor pitch away from the outlet
- A roof valley concentrating runoff into a short section
- Too little gutter or downspout capacity for the layout
If the issue is already affecting water flow or the gutter is physically damaged, see our gutter repair page.