Should I reuse an old plumbing drain or replace it?
Old drains that still function visually appear rough or uncertain, leaving homeowners unsure whether to build over them or dig them up. This uncertainty makes it difficult to decide whether to trust existing plumbing or risk major teardowns.
What the numbers show
Counted from the threads quoted below. How we count
- People have been saying this in most months since September 2026.
- This comes up 14.4× more often in r/Plumbing than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1installing a new shower over the old drainDid this help you?
- 2digging out the old pipe and replacing it with new PVCDid this help you?
- 3continuing to use the old pump without replacement ("riding the lightning")Did this help you?
- 4tightening the packing nutDid this help you?
- 5leaving the valve aloneDid this help you?
- 6installing a catch and drain panDid this help you?
- 7performing annual maintenanceDid this help you?
- 8checking connection points and the bottom of the tank for active leaksDid this help you?
- 9Tapping the metal to test integrityDid this help you?
- 10Installing a flange spacer with a gasket or siliconeDid this help you?
- 11Using an extra thick wax ring to ensure a proper sealDid this help you?
- 12Repainting the doors multiple timesDid this help you?
- 13Keeping existing functional doors to avoid the cost of replacementDid this help you?
- 14delaying replacement and monitoring the pipesDid this help you?
- 15Replacing all accessible copper drain pipes with PVCDid this help you?
- 16Using new parts to replicate the existing copper setupDid this help you?
- 17Snaking the main line through the roof vent.Did this help you?
- 18Seeking a second opinion from family members or online communities.Did this help you?
- 19Searching for hidden or buried cleanouts to clear the line more effectively.Did this help you?
- 20Spot-fixing the broken pipe and airing out the surrounding wood instead of replacing it.Did this help you?
- 21Painting or sealing dried joists to trap potential mold.Did this help you?
- 22Testing water pH and chlorine levels with a kit to rule out acidic water.Did this help you?
- 23Adding a thin metal repair bracket on top for support.Did this help you?
- 24Sneaking a washer in underneath the anchors.Did this help you?
- 25Leaving it alone if the rust is only surface-level.Did this help you?
- 26Asking multiple contractors for quotes and recommendationsDid this help you?
- 27Consulting online forums to verify if contractors are giving good adviceDid this help you?
- 28Flushing and reusing the existing pipes if they are accessible and the correct sizeDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“There is an old stand up shower drain. The drain still drains but it’s real rough. Should I put a new shower over it or is it done for?”source ↗
“Do I replace a sump pump primary and get a secondary battery backup? Current pump is 20 years old. Over the last 2.5 years it’s turned on 1 time. I can’t test due to being sealed from radon system. Basement is finished.”source ↗
“Main question is do I have it replaced or keep riding the lightning.”source ↗
“Copper for drain is your biggest problem. It get paper thin and leaks when you don't expect it.”source ↗
“Had blockage and water coming up in both shower drains.”source ↗
“He took a video and was recommending that we replace all cast iron piping.”source ↗
“6 weeks later everything backing up again and he was saying its because the pipes are caked with gunk, etc.”source ↗
“Asking for advice and if this full piping replacement is necessary.”source ↗
“Had some water come from celling and my husband ripped out the flooring.”source ↗
“We have had a plumber out to replace the pipe but he said our pipes aren’t great all over really.”source ↗
“We are debating whether to change all the piping.”source ↗
“I’m a little nervous because I’ve dealt with water damage before and would rather replace it proactively than have the tank fail and cause a bigger problem.”source ↗
“Mainly trying to figure out whether I’m being overly cautious or whether this is a “replace it before it leaks” situation.”source ↗
“I’m just scared cuz my first place , the water heater cracked and cost us 50k remediation”source ↗
“Replacing toilet and feel like I have to do a repair here but not sure.”source ↗
“Do I have to cut it out or will it pop off?”source ↗
“But want to know if we can wait a year.”source ↗
“Even the copper drains pipe?”source ↗
“I just checked and most of my drain lines are copper except down in the basement.”source ↗
“We had a similar situation with a water leak. After fixing the leak, we let the wood dry out and put a coat of left over paint on it.”source ↗
“When I took off the toilet cleaned up some of the wax, I could see that the flange had some rust on it. Should I hire a plumber to change out the flange?”source ↗
“It sits 3/8 above the floor currently. Would adding a bracket put it too high?”source ↗
“I'm concerned when opened to wash outside wall, it will seep water again, and possible develop into a leak.”source ↗
“The door seems sturdy and there is no draft that I know of. Door looks good as well. But my neighbors seem to have fancy doors and all relatively new. Am’I missing something? Should I be looking at new doors?”source ↗
Where this came up
People with this problem also raised
- 18Should I replace old asbestos-wrapped ductwork while walls are open?
- 2Should I remove an old mixing valve during a renovation?
- 3Do rusty pipes need to be replaced if they aren't leaking?
- 5Slow drip on sewer pipe joint
- 7Should I replace my oil boiler or repair it?
- 10Rebuild original vintage part or buy cheap reproduction?