Gutters collect roof water, but downspouts decide where that water goes. A system can have clean, correctly pitched gutters and still create problems if the outlets are restricted or the downspouts discharge in the wrong place.
Common downspout bottlenecks
- Too few outlets on long gutter runs
- Small outlets connected to a larger gutter
- Restrictive elbows or crushed sections
- Downspouts that terminate at a walkway or foundation edge
- Extensions that are missing, disconnected or poorly routed
More gutter capacity may require more downspout capacity
Moving from a 5-inch to a 6-inch gutter can increase storage and flow capacity, but the advantage is limited if the outlet and downspout remain the bottleneck. The whole path should be considered together.
Urban lots need practical routing
On tighter properties, there may be fewer places to discharge roof water without creating a problem at a doorway, neighboring property or hardscape. The route should be planned before adding outlets or relocating downspouts.
See downspouts and extensions and gutter drainage solutions for the service side of this work.