How to fix a sink drain pipe that is too short
Drain pipes that are a fraction of an inch too short lack the proper engagement depth to stay securely connected under vibration or pressure. This causes the slip joint to periodically work loose and leak, forcing constant manual checks and makeshift fixes.
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.
- 1Placing a pan underneath the leaking joint to catch waterDid this help you?
- 2Using a rubber boot held down with strapping to bridge the gapDid this help you?
- 3Using a slip joint extensionDid this help you?
- 4Using a coupling to extend the copper pipe and soldering on a MIP at the correct distanceDid this help you?
- 5Using a diverter spout with an internal O-ring or ring tightened to the pipeDid this help you?
- 6Using SharkBite fittings to extend the pipeDid this help you?
- 7Running new copper from the 90-degree elbow in the wallDid this help you?
- 8Trimming down two pipes and connecting them together to bridge the gap.Did this help you?
- 9Using an offset flush pipe connector or a matching brass extension slip-joint coupling.Did this help you?
- 10Building out a mount for the cistern to bring it closer to the toilet so the supplied pipe fits.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.
“So my new drain assembly is a bit short. What’s the easiest part to grab to extend and seal this up?”source ↗
“I left me only with an inch of copper pipe for the shower faucet.”source ↗
“I tried both the old spout and bought a new one and both were not sitting on straight and would fall off if I put the water pressure to about 75%.”source ↗
“I am so lost I did buy one that apparently works for 1” length pipes but it won’t come until the 7th at the latest and I don’t even know if it’ll work yet.”source ↗
“All I want to do is shower in my own shower.”source ↗
“So i put in a new sink a little while ago. I think from the picture you can see the right pipe is just a hair short like 1/2 to 3/4 inches. Every so often it works its way loose and leaks (hence the pan).”source ↗
“Due to the position of the old toilet waste pipe, the toilet needs to be positioned a small distance from the back wall and the cistern.”source ↗
“The pipe the toilet has been supplied with is too short.”source ↗
“I've tried to find an equal L shape to replace it with but they don't seem to exist in 38mm brass.”source ↗
“We have been supplied with two, I wondered if there was a way of trimming one down and connecting them to bridge the gap?”source ↗
Where this came up
People with this problem also raised
- 2Converting a bathtub to a shower with a 1 1/4 inch drain
- 9Why can't I replace a flexible sink drain with rigid PVC?
- 2Will twisting a trap cause toilet water to clog my shower?
- 14How to connect a sink drain to existing glued PVC pipes
- 7Kitchen tap internal pipe disconnected with no slack
- 126How to fix a leaking water pipe in a tight space