Downspout repair
A downspout that leaks at a joint or empties at the wall sends the whole roof's rain to the one place you do not want it.
Most downspout problems are a clog, a loose joint or an outlet that drops water at the foundation. And all three are simple to spot from the ground. Fix them before you think about anything underground.
This page prints no prices. It walks through the faults in the order they are worth checking.
Watch it work in the rain
The fastest test costs nothing. Stand outside during a hard rain and watch the downspout. Water pouring over the top of the gutter, spraying from a joint or splashing right at the wall tells you where to start.
If it is dry outside, run a garden hose into the gutter above the downspout. You will see the same faults in a few minutes.
The usual faults
- A clog of leaves and grit, often at the elbow near the top or bottom.
- A joint that has pulled apart, so water sprays out the side.
- A pipe crushed, dented or split by ice or a ladder.
- Straps that have loosened, leaving the pipe leaning away from the wall.
- An outlet that stops right at the foundation.
Notice the last one. A downspout can be perfectly sound and still be the cause of a wet basement.
Clearing and refastening
Clear a clog from the top with a hose or a plumber's snake, then flush it from the bottom to confirm it runs clear. Pull apart sections that have jammed rather than forcing a tool through them.
Refit any joint that has separated. Fasten sections so the upper piece sits inside the lower one, which lets water run down and not out. Add straps where the pipe wobbles. The parts of a gutter page names each piece so you can describe what you need.
Where the water should go
Repairing the pipe is half the job. The outlet must carry water well clear of the wall, onto ground that slopes away. A short extension or a splash block is the minimum, and the downspout drain pipe page covers the longer options.
If the pipe goes underground, a crack can send water into the soil beside the footing without any sign above. The buried downspout drain page explains how to test one. Take a position: replace a badly dented section, do not hammer it back into shape.
When the gutter is the real problem
A downspout cannot carry what the gutter never delivers. If water goes over the edge before it reaches the pipe, read gutter overflow before replacing anything.
Where to stop and call someone
Work on a tall downspout means a long ladder, so use a helper or hire someone. If the basement stays wet after the downspouts and the slope are sound, the cause is deeper. Do not dig beside a wall that is cracked or bowed. That is a question for a licensed structural engineer, and an independent one has no repair to sell you. Where roof water may be discharged is set locally, so ask your building department.
Frequently asked questions
Why is my downspout leaking at the joint?
The sections have likely pulled apart or were fitted the wrong way round. Refit them so the upper piece sits inside the lower one and add straps.
How do I clear a clogged downspout?
Flush it from the top with a hose or work a plumber's snake through. Then flush it again from the bottom to confirm the water runs freely.
Can a downspout cause a wet basement?
Yes. Even a sound downspout is a problem if it empties at the foundation. It sends the whole roof's rain to one spot beside the wall.
Should I repair or replace a dented downspout?
Replace a badly dented or split section. Hammering it back into shape rarely gives you a smooth, leak-free pipe.
Where can roof water be discharged?
Rules are local. Ask your building department before sending water to the street, a neighboring lot or a storm drain.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- US EPA. What You Can Do to Soak Up the Rain
- US EPA. Soak Up the Rain. Managing stormwater around a property