Bang is near the bottom
The lower section or extension jumps when wind catches it, and the sound is strongest near grade level.
Start here: Start with the extension connection, lower elbow, and the last support point above it.
Outdoor
Downspout Bangs in Wind
Direct answer: A downspout that bangs in wind is usually loose at a strap, elbow, or extension, so the metal or plastic is slapping the wall, gutter outlet, or itself. Start by finding the exact section that moves, then tighten, re-secure, or replace only that piece.
Most likely: The most likely cause is a loose downspout strap or a lower extension that is free to swing when gusts hit the wall side of the house.
Stand back during a breezy period and watch where the movement starts. A little flex is normal. Sharp banging, clacking, or wall-thumping is not. Reality check: one loose strap can make a lot more noise than you would expect. Common wrong move: stuffing foam or random shims behind the downspout without fixing the loose support that caused the movement.
Don’t start with: Do not start by replacing the whole downspout. Most wind noise comes from one loose support point or one rattling joint.
If the noise is low near the groundCheck for a loose downspout extension first.
If the noise is higher on the wallCheck the upper straps and elbow joints before anything else.
Last reviewed: 2026-04-05
What the banging sounds like and where to start
Bang is mid-wall
You hear a repeated knock against siding or masonry, usually where the downspout runs straight down the wall.
Start here: Start with the wall clearance and each downspout strap along that run.
Bang is near the top elbow
The noise is sharper and higher up, often where the downspout turns from the gutter outlet into the vertical run.
Start here: Start with the upper elbow joints and the first strap below the gutter outlet.
Noise happens only in strong gusts
The downspout looks mostly fine in calm weather, but a hard side wind makes it slap or chatter.
Start here: Start by checking for a section that is secure at one point but free to swing between supports.
Most likely causes
1. Loose downspout strap
This is the most common cause. When a strap loosens or pulls away, the downspout can swing just enough to hit the wall or chatter at the fastener.
Quick check: Grab the downspout near each strap and try to move it side to side. Excess play at one strap usually points right to the problem spot.
2. Free-swinging downspout extension
Lower extensions catch wind easily, especially lightweight plastic or loosely connected metal pieces. They can slap the elbow, wall, or ground.
Quick check: Lift and wiggle the extension by hand. If it shifts easily or drops out of alignment, that is a strong noise source.
3. Loose downspout elbow or connector joint
A joint can stay connected but still rattle if the seam is loose or one section is not seated fully. Wind turns that small looseness into a sharp metallic knock.
Quick check: Press on each elbow and connector. If the sound changes or the joint clicks, that joint needs attention.
4. Downspout run too close to the wall or siding
Even with decent straps, a slightly bowed section can tap the wall in gusts. This is common after minor impact, seasonal movement, or a past reattachment that left poor spacing.
Quick check: Look for rub marks on siding, brick, or the downspout face where contact is happening.
Step-by-step fix
Step 1: Pin down the exact section that moves
You want the first moving point, not just the loudest sound. Wind noise often echoes off the wall and makes the source seem higher or lower than it is.
- Watch the downspout during a breezy period from a safe spot on the ground.
- If wind is calm, gently push the downspout and extension by hand to mimic the movement.
- Look separately at the top elbow, each wall strap, the straight run, and the lower extension.
- Check for fresh rub marks, chipped paint, shiny metal spots, or scuffed siding where contact is happening.
Next move: If you can identify one section that starts the movement, move to the matching support or joint in the next steps. If the whole run moves and you cannot tell where it starts, begin at the top and check every strap and joint in order.
What to conclude: A single loose point usually causes the banging, even if several sections seem to shake once the wind gets hold of it.
Stop if:
- The downspout is partly detached from the wall.
- The upper section is pulling away near the gutter outlet.
- You would need to climb in windy conditions to inspect it safely.
Step 2: Check the downspout straps and wall attachment points
Loose or missing support is the most common fixable cause, and it is usually visible without taking the downspout apart.
- At each downspout strap, try to move the downspout side to side and away from the wall.
- Look for a strap that is bent open, missing a fastener, or no longer snug to the downspout.
- Check whether the wall fastener is loose in siding, trim, masonry joint, or wood backing.
- Tighten a loose fastener if it still bites firmly. If the strap is bent or no longer holds the downspout snug, plan to replace that downspout strap.
Next move: If tightening or re-securing the strap stops the movement, you likely found the main cause. If the straps are solid but the noise remains, the problem is more likely at a joint or the lower extension.
What to conclude: A strap that no longer holds the run close and steady lets the downspout build momentum and bang in gusts.
Step 3: Check the lower extension and bottom elbow for swing
The lower end catches the most wind and often makes the loudest bang, especially when an extension is loose but not fully disconnected.
- Lift the downspout extension and see whether it fits tightly at the elbow or connector.
- Check whether the extension is twisted, cracked, or sitting partly out of the joint.
- Look for a lower elbow that rocks or clicks when you press on it.
- If the extension is the only loose piece, remove and reseat it squarely. Replace it if it will not stay aligned or has worn, split, or deformed ends.
Next move: If the noise stops after reseating or replacing the extension, the rest of the downspout may be fine. If the lower section is secure but the noise continues, inspect the upper elbow and any mid-run connector next.
Step 4: Inspect elbow and connector joints for rattle or poor fit
A joint can look connected from a distance but still chatter if it is loose, spread open, or not seated fully.
- Press each elbow and connector joint by hand and listen for clicking or metal-on-metal chatter.
- Check for gaps at the seam, misalignment, or a joint that slides too easily.
- Reseat a shifted joint if it can be aligned without forcing it.
- If one elbow or connector stays loose after reseating, replace that specific downspout elbow or downspout connector rather than the whole run.
Next move: If the joint becomes snug and the banging stops, you have a localized repair. If the joints are snug and the noise is still a wall-thump, the downspout likely needs better spacing or support at the contact point.
Step 5: Secure the confirmed loose section and test on the next windy day
Once you know whether the problem is support, a joint, or the extension, the fix is usually straightforward. The goal is a snug run with a little room for drainage, not a rigid over-tightened assembly.
- Replace the failed part that matches your diagnosis: downspout strap, downspout extension, downspout elbow, or downspout connector.
- Keep the downspout aligned so it is supported without pressing hard against siding or masonry.
- After the repair, push the downspout by hand again. It should move only slightly and should not click, slap, or rock at the repaired point.
- Check again during the next windy period. If the noise is gone, you are done. If the downspout still bangs and the wall contact is coming from a bent or poorly routed run, plan a more complete rehang or call a gutter pro.
A good result: If the repaired section stays quiet in wind, the problem was local and the rest of the assembly can stay in service.
If not: If noise remains after the obvious loose point is fixed, there may be a hidden misalignment, a disconnected section, or a drainage issue adding weight and movement.
What to conclude: A quiet test after repair confirms you fixed the actual moving point instead of just muffling the symptom.
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FAQ
Why does my downspout only bang when the wind comes from one direction?
That usually means one section has just enough play to swing when gusts hit the broad side of the downspout or extension. The loose point is often a strap, lower extension, or elbow joint rather than the whole run.
Is a little downspout movement normal in wind?
Yes. A small amount of flex is normal. Loud knocking, repeated clacking, or the downspout hitting the wall is not. Once you hear sharp impact noise, something is too loose or too close to the wall.
Can I just wedge something behind the downspout to stop the noise?
Not as a real fix. A temporary shim may quiet it for a while, but if the strap or joint is loose, the movement usually comes back. It is better to secure the actual loose support point and keep proper wall clearance.
What part is most often bad when a downspout bangs in wind?
The most common culprit is a loose downspout strap. After that, a free-swinging downspout extension or a rattling elbow joint is next on the list.
Should I replace the whole downspout if it keeps making noise?
Usually no. Most wind-noise problems are local. Replace the failed strap, extension, elbow, or connector that you confirmed is moving. Replace the whole run only if several sections are bent, detached, or badly misaligned.