A clean gutter feeding a blocked downpipe will still overflow. That's why we test every downpipe after a gutter clear, and why some customers who've had their gutters done still see water pouring over the edge.
Signs your downpipe is blocked
These are all visible from the ground, ideally in steady rain.
- The downpipe is silent while others on the house are running.
- The gutter overflows along its whole length, not at one spot.
- Water leaks or sprays out of the joints partway down the pipe.
- Moss or debris is sticking out of the top of the outlet.
- Damp or green staining down the wall beside the pipe.
What causes it
Most blockages are the same material that fills gutters: broken-up roof moss, leaves and tile grit. It washes into the outlet and catches at the first bend (the swan neck under the eaves) or at the shoe at the bottom. Over a few months it sets into a plug.
Downpipes that run into an underground drain can also back up if the gully at the bottom is silted — the downpipe itself may be clear.
How we clear and test them
After clearing the gutter we run water through each outlet and watch it come out at the bottom. If it doesn't flow, we clear the blockage from the top or bottom of the pipe and test it again. If the problem turns out to be in the underground drain, we'll tell you rather than charge for something we can't fix.
The short version
- A silent downpipe in rain is the clearest sign.
- Clearing the gutter alone won't fix a blocked downpipe.
- We flow-test every downpipe on every gutter clear.
