Pipes Under Sink Keep Coming Apart: Here’s a Quick Fix


Cue horror music, headaches, insomnia, and what we call the plumbing panic. The under-sink pipes that start and keep coming apart can wreak havoc on any household. Even more so if you’re not too skilled of a plumber and have no idea what’s wrong.

The most frequent reason why the pipes under your sink keep coming apart is a worn-out connector. A drain poorly sealed with plumber’s putty can also come loose and leak constantly. Another reason is the damage you can make while moving stuff around the under-sink cabinet.

3 Reasons Why Pipes Under Kitchen Sink Come Loose

Loose pipes under the sink are nothing short of a nightmare, but you don’t need advanced plumbing knowledge to fix the issue. Before rolling up your sleeves and getting ready to intervene, you should figure out why the pipes come loose, though. Here are the most frequent reasons.

1. Worn-Out Washers or Nuts

Plumbing connectors are those things keeping the pipes under the sink connected to the flange’s tailpiece. In most cases, they are nylon washers and steel ring nuts. 

Most plumbing installations use both fastener types, with the steel ring nuts tightened over the nylon washers. 

When either of these two becomes worn out, the pipes begin to come loose and leak. You may not detect the leak at first because the amount of water getting out from the joint isn’t enough to create a puddle. However, you could still feel the leak if you touch the pipe, which will feel wet.

Over time, the damaged washer or nut will become looser and looser, and you’ll eventually end up with a puddle on the cabinet’s floor or a true flood when you’re running the tap.

To fix this issue, you have to change the broken nut or washer. If you’re not sure which is faulty, change both.

2. Poorly Sealed Drain 

While most drain pipes attached to the tailpiece don’t need other sealing apart from the nylon washer and steel ring nut, some plumbers prefer sealing it with plumber’s putty rather than washers. In some cases, they might also use plastic cement, which is usually employed when sealing rough-in plumbing. 

The same goes for other pipe sections, including the joint between the pipe linking the tailpiece to the P-trap and the one linking the P-trap to the wall drain. 

If your plumber used plumber’s putty on any of these joints, chances are it was too thin to start with, or it has dried over time. Cracks and small holes in this sealant allow water to escape, leading to constant leaks. 

Moreover, dried-out or thin putty may also cause the pipes to come loose constantly. You’ll have to take all sections apart and reassemble the under-kitchen plumbing the right way to fix the issue.

3. Physical Damage

If you’re one of those super-organized homeowners who keep nothing in the cabinet under their sink, you can skip this and read below. However, if you’re like us and use the under-sink cabinet to store cleaning supplies, other chemicals, and perhaps even some shopping bags, then you can damage the plumbing as you’re rummaging through that stuff.

Damages are not always visible, but under-sink plumbing is a delicate system. The nylon washers or fasteners could break as you’re shaking the pipes, and you’ll end up with an ad-hoc indoor pool the next time you open the tap.

To fix the issue, you’ll first have to repair whatever you’ve broken, then tidy up and organize the space under your sink. Consider using baskets and cabinet organizers to keep everything at hand. Keeping the cabinet clean and tidy also makes it easier to empty it each time you call in a plumber or fix something.

Will Tightening the Sink Connections Fix the Problem?

Tightening the sink connections might fix the problem, but this isn’t always the case. First, you have to figure out why the pipes come loose. 

For instance, the problem could be the putty if they were fixed with plumber’s putty instead of sealed with washers and fastened with nuts. In this case, popping a nut on the pipe and tightening it may provide a temporary solution. However, since there is no washer in place, the pipe will start leaking again eventually.

This is why you should focus on stopping the leak and fixing the entire under-sink plumbing if necessary to prevent future problems. 

How to Fix Disconnected Pipes Under Sink (5 Easy to Follow Steps)

Leaking pipes under the sink seem like a serious problem, but if they’re loose, the issue is easier to fix than you think. And the best part? You may be able to fix it yourself without calling in a professional. Here’s how to do it.

Tools Required to Fix Disconnected Pipes

  • Large adjustable pliers
  • Nylon drain washers
  • Ring nuts
  • Plastic bucket 
  • Rubber gloves 
  • Flashlight (optional)

Step 1 – Find the leak

Finding a puddle under your sink is a good indicator that something is leaking, but you’ll have to find the exact leak point to fix it. 

To do that, clear the area under your sink and place a plastic bucket under the P-trap (the bent piece of pipe found under every sink in your house). Turn on the faucet, then lay down and watch what happens under the sink. 

If the cabinet doors keep the area dark, use the flashlight to get an accurate view. Observe the pipes and connections and see which one leaks.

Step 2 – Tighten the connection 

Once you’ve found the leaking junction, turn off the tap and use the pliers to tighten the connection by turning the nut clockwise. Turn the tap back on and see if the leak persists. If it doesn’t leak anymore, that’s it. You can skip the other steps and celebrate your job. If it still leaks, you’ll have to replace the washer and nut.

Step 3 – Remove the washer and nut

Although the leak could be caused by a damaged nut or damaged washer, it is good practice to replace both of them. Before that, you’ll have to take the old washer and nut off. 

To do that, move the bucket away and turn off the tap. Preferably, you should also turn off the main water supply to prevent getting drenched if someone else opens the faucet accidentally.

Use the pliers to unfasten the ring nut by turning it counterclockwise, then separate the connection by hand.

Step 4 – Replace the nut and washer 

Remove the old nut and washer from the pipe section and slip in a new ring nut. Place a new nylon washer against the nut, then thread the connection by hand.

Tighten the nut by hand as much as you can, then use the pliers to tighten it securely by turning the nut clockwise. 

Step 5 – Check the outcome 

Place the bucket back under the sink and turn on the faucet (don’t forget to turn on the main water supply if you’ve closed it). Inspect the connection for any leaks. Repeat these steps or call in a plumber if you haven’t managed to solve the issue.

How to Secure Kitchen Sink Pipes that Keep Coming Apart

While you now know how to fix disconnected pipes under the sink, here are a few tips and techniques to help you along the way.

Always replace the entire washer and nut combo

Because it is often hard to tell whether it’s the washer or nut’s fault when pipes come loose under the sink, it is always a good idea to replace both of them.

Fix temporarily with plumber’s putty 

If you found the leak but don’t feel like fixing it yourself, plumber’s putty can provide a temporary solution until the plumber comes in. 

Turn off the tap and dry the pipes with a rag. Then, roll a dollop of putty to form a putty string and place it around the offending joint. Press with your fingers and let it harden as instructed. The putty placed this way won’t hold on forever, but you can enjoy a leak-free sink for a couple of days. 

Avoid using silicone to seal the joints 

Like plumber’s putty, silicone provides a water-tight seal that can take you through the crisis. However, silicone is harder to apply than putty (it won’t adhere if the pipes aren’t completely dry) and harder to remove.

Moreover, silicone could also leak into the pipe as you’re applying it. If this happens, you might have to replace the entire pipe section if you’re not able to remove it completely. Otherwise, it might prevent the new washer from sealing the pipe properly.

Next Steps

Fixing a loose pipe under the sink isn’t complicated, but not everyone is comfortable with it. What do you say? Would you try to fix it yourself, or would you rather hire a professional to do the job?

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