Post By Admin
February 13, 2025Noticed water pooling under your kitchen sink? A pipe leaking under sink can lead to water damage, mold growth, and costly repairs if not addressed quickly.
No matter how small the drip or big the leak, fixing it yourself is often easier than you think. The key is identifying the source, using the right tools, and applying the correct fix.
In this blog, you’ll learn how to spot the problem of pipe leaking under sink, tighten connections, replace worn-out parts, and apply sealants.
However, we’d like to remind you that if you’re dealing with a leak that won’t go away, it’s highly important to call a professional for a thorough leak detection service.
How to Fix a Leaking Pipe Under Your Kitchen Sink
No need to panic! Before you start tightening or replacing anything, let’s break down the simple steps to find the leak and fix it the right way:
1. Identify the Source of the Leak
Before you start fixing your leaking pipe, you need to find where the leak is coming from.
- Supply Lines: If the leak is constant, even when the sink isn’t in use, it’s likely from the hot or cold water supply lines. Check for drips coming from the valves or flexible hoses.
- Drain Pipes: A leak that only occurs when water is draining could be due to a loose or damaged U-pipe under sink.
- Seals and Gaskets: Worn-out seals around pipe joints, the sink strainer, or the faucet base can cause leaks. Feel around these areas for moisture.
- Faucet Leaks: Sometimes, a faulty faucet can leak and drip down into the cabinet, making it look like the pipes are leaking.
Once you know the source, you can move on to the best fix.
2. Tighten Loose Connections
One of the most common reasons for pipes under kitchen sink leaking is loose fittings. Over time, vibrations and pressure changes can cause connections to loosen.
Use a wrench to gently tighten the fittings on the PVC pipe under sink, supply lines, and P-trap.
For compression fittings, tighten them by hand first, then use a wrench to secure them further. Be careful not to overtighten, as this could crack the pipe or damage the threads.
3. Replace Worn-Out Washers and Seals
Leaks often happen due to degraded rubber washers and seals. To replace them:
- Turn off the water supply.
- Unscrew the leaky connection and remove the old washer.
- Insert a new washer and reassemble the fitting.
- Turn the water back on and check for leaks.
This simple fix can stop a kitchen sink pipe leaking issue caused by worn-out seals.
4. Apply Plumber’s Tape for a Quick Fix
If you have a small leak in a threaded connection, a plumber’s tape can help seal the gap.
- Wrap the tape around the threads several times before reconnecting the pipe.
- This method works well for minor leaks in drain pipes and supply line connections.
- It’s a temporary solution, so consider replacing any worn-out fittings soon.
5. Seal Small Cracks with Epoxy or Waterproof Sealant
A leaking pipe due to small cracks or pinholes can be fixed with epoxy or waterproof sealant.
- Clean and dry the affected area.
- Apply the epoxy putty or sealant, ensuring it covers the crack completely.
- Let it cure for the recommended time before running water through the pipe.
This method is great for minor PVC pipe under sink leaking issues but won’t work for large cracks or serious damage.
6. Replace the Damaged Drain Pipe
If your drain pipe is cracked or beyond repair, replacing it is the best option.
- Turn off the water and place a bucket under the pipe to catch any remaining water.
- Unscrew the fittings and remove the damaged sink pipe leaking section.
- Install a new pipe and apply the plumber’s putty to ensure a watertight seal.
- Reconnect everything and test by running water through the sink.
This step is necessary if your U-pipe under the sink is leaking due to cracks or corrosion.
7. Call a Professional for Severe Leaks
If you’ve tried these fixes and your kitchen sink pipe is still leaking, it may be time to call a plumber.
A persistent leak could mean deeper plumbing issues that require expert attention. If needed, you can check out our guide on how to fix a leaking pipe for more details.
FAQ about Leaking Kitchen Sink
Still have questions? Here are some common concerns homeowners have about leaking kitchen sink:
1. Is a kitchen sink leak an emergency?
It depends on the severity. A slow drip may not be urgent, but a major kitchen sink pipe leaking can cause serious damage and should be fixed immediately.
Water damage can spread quickly, leading to structural problems and mold growth.
If water is pooling or soaking into your cabinets and flooring, address the issue as soon as possible to prevent costly repairs.
2. What is the most common leak under the kitchen sink?
Loose connections in the U-pipe under sink, worn-out washers, and cracks in drain pipes are the most frequent culprits.
Regular maintenance and quick fixes can prevent small leaks from turning into larger plumbing problems.
Always inspect your plumbing system periodically to catch issues before they become severe.
3. Can a water leak go away on its own?
No. Water leaks don’t fix themselves and will worsen over time, leading to higher repair costs.
Even a minor leak can erode plumbing materials, cause mold growth, and damage nearby structures.
If left unchecked, a small issue can become a major plumbing emergency that requires professional repair.
4. How do you temporarily fix a leaking sink?
Use a plumber’s tape, epoxy, or a bucket to catch the drips while you plan for a permanent repair.
If the leak is coming from a connection, tightening the fittings may help reduce the problem temporarily.
However, a true fix requires replacing faulty components or sealing cracks properly.
5. What is the best sealant for a leaking sink?
A high-quality silicone-based waterproof sealant or epoxy putty works well for sealing minor leaks. Look for a product that is durable and designed for plumbing applications.
Silicone sealants provide flexibility, making them ideal for areas that experience movement or pressure changes.
Conclusion
A leaking pipe under the sink can be frustrating, but with the right tools and knowledge, you can fix most issues yourself.
By identifying the leak source, tightening connections, replacing seals, and applying quick fixes, you can save more time and money.
However, if you’re dealing with a major issue, it’s best to seek professional help. For reliable plumbing services, you can rely on Neighbourhood Plumbing.
So, contact us today!
About the Author
From unclogging the toughest drains to repairing leaking toilets, Ricky is a seasoned plumber who has brought his craftmanship to homes across Melbourne. He is passionate about sharing plumbing tips just as much as he is about fixing your plumbing issues. So, when your taps or pipes begin leaking, you know who to call.
