Work gloves
Use it for: Protects your hands while digging and handling sharp metal or plastic edges.
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How to Replace a Buried Downspout Extension Outlet Elbow
To replace a buried downspout extension outlet elbow, uncover the elbow, confirm it is cracked, crushed, loose, or badly clogged, then install a matching replacement and test it with a steady flow of water.
This is usually a manageable yard repair if the damage is right at the outlet connection and the buried drain line itself is still sound. The main job is exposing the elbow without damaging the pipe, then matching the new part so water leaves the downspout cleanly.
Before you start: Match the elbow angle, downspout size, and the drain pipe connection style before ordering. Compare rectangular to round transitions and corrugated versus smooth pipe ends.
Safety first
- Wear gloves when handling metal downspouts, screws, and buried fittings.
- Dig carefully around buried pipe so you do not crack the line while exposing it.
- Do not leave an open hole unattended where someone could step into it.
- Stop if the soil is washing out badly or the area around the foundation seems unstable.
Tools you may need
Hand trowel or small shovel
Use it for: Lets you uncover the elbow carefully without gouging the drain pipe.
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Tape measure
Use it for: Helps you match the elbow size and pipe connection before buying or installing the replacement.
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Utility brush
Use it for: Useful for cleaning dirt and debris off the pipe ends before fitting the new elbow.
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Hose with spray nozzle
Use it for: Lets you flush the line and test the new elbow under real water flow.
Shop a hose nozzle
Nut driver or screwdriver
Use it for: Needed if your elbow uses screws or clamps at the downspout connection.
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Step-by-step fix
Step 1: Confirm the outlet elbow is the part that failed
- Look at the bottom of the downspout where it turns into the buried drain line.
- Check for a cracked elbow, a crushed bend, a loose connection, or an elbow packed with roots, mud, or roof grit that cleaning will not solve.
- Run water from a hose into the downspout for a minute and watch the elbow area for leaks, backup, or water spilling out at the joint.
- If the elbow is visibly damaged or leaking at the fitting while the rest of the line seems intact, this is the right repair.
If it works: You have confirmed the buried downspout extension outlet elbow is damaged or worn out and is the likely cause of the drainage problem.
If it doesn’t: If the elbow looks sound but water still backs up, the buried drain line farther downstream may be clogged or collapsed and should be cleared or inspected before replacing parts.
Stop if:
- The buried pipe is crushed, split, or offset below the elbow.
- You find major root intrusion, standing water that never drains, or a sinkhole around the line.
- The downspout itself is loose from the wall or the surrounding soil has washed out enough to create a safety hazard.
Step 2: Expose the elbow and clear the work area
- Put on gloves and use a hand trowel or small shovel to remove soil around the elbow.
- Dig slowly around the sides and bottom so you can see the full connection to both the downspout and the buried pipe.
- Brush off packed dirt and remove leaves, stones, and mulch from the opening so nothing falls into the line during the swap.
- Set the removed soil on a tarp or in a pile nearby so backfilling is easier later.
If it works: The elbow and both connection points are exposed enough to remove and replace the part cleanly.
If it doesn’t: If you still cannot see where the elbow joins the buried pipe, keep widening the hole rather than prying on the fitting blindly.
Stop if:
- You uncover broken pipe beyond the elbow connection.
- The soil keeps collapsing into the hole and makes the area unstable to work in safely.
Step 3: Remove the old elbow and match the replacement
- Loosen any screws, clamps, or fasteners holding the elbow to the downspout.
- Twist and pull the old elbow free. If it is stuck, work it loose gently instead of forcing the buried pipe sideways.
- Measure the downspout opening and the drain pipe connection, and compare the bend angle and end style with the new elbow.
- Clean both mating surfaces with a brush so the new elbow can seat fully.
If it works: The old elbow is out and you have a replacement that matches the size, angle, and connection style.
If it doesn’t: If the new elbow does not slide onto both ends properly, recheck the pipe size and whether the buried line uses corrugated or smooth-wall fittings.
Stop if:
- The downspout outlet or buried pipe end is cracked badly enough that the new elbow cannot attach securely.
- Removing the elbow exposes hidden damage that extends beyond this one fitting.
Step 4: Install the new buried downspout extension outlet elbow
- Dry-fit the new elbow first to make sure it lines up without forcing the downspout or buried pipe out of position.
- Attach the elbow to the buried pipe and downspout in the same orientation as the old part so water flows downhill into the line.
- Reinstall screws or clamps if your setup uses them, and tighten them snugly without crushing the fitting.
- Make sure the elbow is fully seated and not twisted, tilted, or under tension from misalignment.
If it works: The new elbow is installed squarely and feels secure at both ends.
If it doesn’t: If the elbow keeps popping loose or sitting crooked, adjust the downspout alignment and remove more soil around the pipe so the connection can sit naturally.
Stop if:
- You have to force the parts together hard enough to bend the downspout or shift the buried pipe.
- The replacement cannot be secured because the surrounding pipe ends are too damaged or misshapen.
Step 5: Backfill carefully and protect the connection
- Add soil back around the elbow a little at a time, packing it lightly by hand to support the fitting without knocking it out of place.
- Keep rocks, broken concrete, and other sharp debris away from the elbow and pipe connection.
- Shape the top soil so water sheds away from the foundation and does not pool around the downspout outlet.
- Leave the final few inches loose enough that you can still inspect the joint during testing if needed.
If it works: The elbow is supported by the surrounding soil and the area is ready for a water test.
If it doesn’t: If the elbow shifts while backfilling, uncover it again and reset the fitting before adding more soil.
Stop if:
- Backfilling reveals the pipe run is misaligned enough that the elbow cannot stay connected under normal soil pressure.
Step 6: Test the repair under real water flow
- Run a hose into the downspout for several minutes to simulate a strong rain.
- Watch the elbow area for leaks, overflow, bubbling soil, or water backing up at the downspout.
- Check the discharge point at the far end of the buried extension, if accessible, to confirm water is moving through the line.
- Finish backfilling and restore mulch or surface cover once the connection stays dry and the line drains normally.
If it works: Water moves through the new elbow without leaking or backing up, and the repair holds under steady flow.
If it doesn’t: If water still backs up, the buried line downstream likely needs cleaning, flushing, or inspection for a blockage or collapse.
Stop if:
- Water immediately surfaces from the ground near the buried line.
- The elbow stays dry but the system cannot carry water away, pointing to a larger drain failure beyond this repair.
Replacement Parts
Find a buried downspout extension outlet elbow on Amazon
Match the elbow angle, downspout size, and the drain pipe connection style before ordering. Compare rectangular to round transitions and corrugated versus smooth pipe ends.
As an Amazon Associate I earn from qualifying purchases. Repair Riot may earn a commission at no extra cost to you.
Verify the repair
- The new elbow fits without forcing the downspout or buried pipe out of alignment.
- Water runs through the connection without leaking at the joint.
- No water pools at the foundation during the test.
- The far end of the buried extension discharges normally, if visible.
- The elbow stays in place after backfilling and a second water test.
FAQ
How do I know the elbow needs replacement instead of just cleaning?
Replace it if it is cracked, crushed, split, badly warped, or too clogged to clear fully. If the elbow is intact and only packed with debris, cleaning may be enough.
Do I need to dig up the whole buried downspout extension?
Usually no. If the problem is limited to the outlet elbow at the base of the downspout, you only need enough access to remove and reconnect that fitting. If water still backs up after replacement, the buried line may need more work.
Can I reuse the old screws or clamps?
You can if they are not rusted, stripped, or bent. If they no longer hold the connection snugly, replace them so the elbow stays secure.
What if I cannot find an exact matching elbow?
Match the downspout size, bend angle, and the buried pipe connection style as closely as possible. The replacement needs to fit both ends without forcing either side out of line.
Why does the new elbow leak even after I installed it?
The most common causes are a poor size match, a crooked connection, debris left on the pipe ends, or damage to the downspout or buried pipe beyond the elbow itself.