When homeowners report overflowing gutters, the first assumption is usually that the gutters themselves are blocked. In many cases, however, the real culprit is a blocked downpipe. Understanding the difference matters — because a blocked downpipe won't be fixed by simply scooping debris out of the gutter run.
Downpipes — the vertical pipes that carry water from gutters to ground level drains — are particularly prone to blockage at junctions, bends, and at the point where water enters from the gutter. Debris that passes through the gutter can collect and compress at these points, forming a solid mass that prevents water from draining. A blocked downpipe causes the gutter above to fill and eventually overflow, even if the gutter itself is clean.
The main causes of downpipe blockages are accumulated leaf and debris washdown, bird nest material (particularly from house sparrows and starlings that nest in the eaves), tennis balls and other foreign objects, and organic growth — particularly moss — that has washed down from the roof or gutter.
Clearing a blocked downpipe typically requires specialist equipment — high-pressure jetting or a drain rod run from the bottom of the pipe. Simply running a hosepipe down from the top is rarely sufficient for a full blockage and can occasionally make things worse by compacting the blockage further.
The most effective solution is preventive — ensuring gutters are cleaned regularly so that large volumes of debris never have the chance to wash down into the downpipe. Installing debris-catching cages at the top of downpipes is also effective, although these require regular inspection and clearing to remain effective.
All of our gutter cleaning visits include a downpipe flush and drainage test as standard. If we identify a downpipe blockage that requires specialist clearing, we'll quote for this on the same visit.