How to connect a sink drain to existing glued PVC pipes
Replacing a kitchen sink often leaves the new drain misaligned with a rigid, glued floor drain system. Because the existing pipes cannot be easily shifted, connecting the trap without making mistakes on the main sewer line becomes a nerve-wracking guesswork project.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 18.7× 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.
- 1cutting the glued connection and using a shielded coupling to transition to slip-jointDid this help you?
- 2Using a Fernco coupling instead of a slip couplingDid this help you?
- 3Reducing the shower drain size to match existing fittingsDid this help you?
- 4Moving the pipe to a different bay and splicing in a new wyeDid this help you?
- 5Using push-fit fittings like SharkBitesDid this help you?
- 6Using adapter fittings with compression or cinch ringsDid this help you?
- 7using an fpt x pvc adapter or mpt x pvc adapterDid this help you?
- 8removing the metal pipeDid this help you?
- 9Take pictures to a plumbing supply store for adviceDid this help you?
- 10Pry out the tailpiece with pliers and a screwdriverDid this help you?
- 11Use a torch to remove a soldered tailpieceDid this help you?
- 12Opening up the wall behind the washer to run the drainDid this help you?
- 13Dropping a pipe under the house to tap into the main drain pipeDid this help you?
- 14Disconnecting the trap and cutting the vertical ABS below the glued joint, then coupling it back with a shielded no-hub couplingDid this help you?
- 15Removing the basket strainer to maneuver the tailpieceDid this help you?
- 16Calling a plumber rather than risking a cracked drain if the ABS is brittleDid this help you?
- 17Getting a second opinion from another local plumberDid this help you?
- 18Attaching threaded connectors to the existing riserDid this help you?
- 19Clarifying the reasoning directly with the plumberDid this help you?
- 20cutting and silver soldering the pipe and then crimpingDid this help you?
- 21buying an adapter like a 1/2 inch FIP by 3/8 outer diameter compression adapterDid this help you?
- 22changing the stop valves to standard sizesDid this help you?
- 23Cutting the old pipe instead of trying to unscrew itDid this help you?
- 24Using a shielded fernco or proflex couplingDid this help you?
- 25Buy a double-ended flanged tailpiece to bridge the gap and raise the tee connection.Did this help you?
- 26Shorten the first extension tube.Did this help you?
- 27Buy multiple different fittings from the store and return the ones that aren't used.Did this help you?
- 28Use a flexible accordion pipe to bridge the gap.Did 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.
“How do I connect the sink drain to the existing floor drain bits? I presume I'll need an s-trap but don't really understand how to connect the trap to the final end?”source ↗
“I bought a new sink and the end does not fit on the pipes that send the water.”source ↗
“This metal pipe appears to be 1 and 1/4 in but my p-trap PVC won't slide into it. Do I need to take this metal adapter or whatever this is off?”source ↗
“I’m trying to replace a corroded brass sink tailpiece that is leaking. But as you can see in the picture, the entire black ABS drain assembly below the tailpiece is completely glued all the way down to the floor drain.”source ↗
“There are no slip joints or nuts to loosen below the tailpiece collar, so I can't drop or swing the pipe out of the way to get the old brass piece out or slide a new one in.”source ↗
“How do I get this old brass piece out without cracking the glued ABS pipes or the sink strainer above it and how do I install the new replacement tailpiece? Since the black pipe can't move, the new piece will be trapped by the same clearance issue.”source ↗
“How likely is it that I could unscrew that galvanized 90 without breaking something? Question 2. Is there a way for me to connect PVC to that galvanized waste line?”source ↗
“I am looking for recommendations on how to connect to the sewer line, including:”source ↗
“which makes me nervous on the main sewer line.”source ↗
“There is no ideal way to connect quest pipe to other piping systems.”source ↗
“Anyone got any advice on how to install the new brass drain assembly to the existing waste drain pipe?”source ↗
“My question is in drainage. The drain pipe is right behind where I want to go. I'm guessing I need to open up the wall to access the pipe and run the drain from the sink to it. It's that correct?”source ↗
“So I need to drop a pipe under the house then tap the main drain pipe?”source ↗
“I thought I had revealed enough so plumber could connect a washbasin pipe to this, one was there originally but was capped off years ago like picture.”source ↗
“Plumber said he needs to get at the 90° collar to replace with another one. Is that correct? Thought he'd be able to connect the threaded collar that's there at the moment.”source ↗
“We have a bathroom roughed in, and want to attach the plumbing to the water. Should we cut into a pipe from the manifold? Looking for help!”source ↗
“Replacing disposal. The new one has its drain sit slightly higher and slightly farther away.”source ↗
“Do i need to redo the right side as well to ensure the T connection lines up better or can I get away with the sloping the pipe over to it?”source ↗
“Trying to avoid using the flexible accordion pipe if possible.”source ↗
“Problem is the pipes are coming in at such an angle from under the house the pipe is cocked too much for my comfort in the shark bites.”source ↗
“Will a loose beadlock join onto my pipe that's 12.2mm in diameter am wanting to fit #8 hose which is 10.3mm internal diameter”source ↗
“And will I need a lip to stop it slipping off ?”source ↗
“I keep getting told I need to cut and silver solder it and then crimp”source ↗
Where this came up
People with this problem also raised
- 3Washing machine drain pipe keeps leaking after putting back on
- 7Kitchen tap internal pipe disconnected with no slack
- 13Best way to seal gaps around pipes under the sink?
- 126How to fix a leaking water pipe in a tight space
- 4How to fix a sink drain pipe that is too short
- 7How to connect a faucet and pipe with different sizes