How to Fix Under the Kitchen Sink Leak

Kitchen Sink Leak
  • Author: Amanda Arnold
  • Posted On: June 7, 2023
  • Updated On: September 28, 2023

Water puddles under the sink is the worst kitchen nightmare for a homeowner. The ‘drip, drip’ due to the kitchen sink leak is frustrating. It needs attention as soon as possible and for this you may not have to wait, if the water damage is serious. 

So when you discover the under the kitchen sink leak, do not underestimate the stains that will be left behind or even the mold. In this guide you will learn to fix a leaky kitchen sink faucet, the causes behind it and how to fix the problem. 

4 Common Reasons of Under the Kitchen Sink Leakage

If you have a witness’s kitchen sink leak from drain or base, ensure to find out the main reason behind this leakage. One may think to replace kitchen sink drain but without knowing the cause, you cannot find the best solution to fix the kitchen sink leak.

Keep in mind that you don’t need to replace your kitchen sink or drain every time you witness a sink leakage. You can simply get rid of the leakage by repairing your sink drain or base. But firstly, understand the following cause of under the kitchen sink leak;

1) Drain Leakage

Inappropriately Installed Connections

The leakage from your kitchen sink drain will occur if you haven’t installed the kitchen sink drain appropriately. While installing the kitchen sink drain, if you have forgotten to apply putty, the chances of the kitchen sink leaking at the drain are higher and water may start dripping under the sink.

On the other hand, the chances for kitchen sink leak from drain will occur if your drain is worn-out or wrecked. If you have installed your old drain to your new kitchen sink faucet, the loose structure might also cause leakage.

2) Inappropriately Installed Connections

Inappropriately Installed Connections

 If you have replaced kitchen sink faucet yourself without proper care, the chances for under the kitchen sink leak are higher. The reason could be due to the inappropriately installed water connections or supply lines. If the connection pipes have loose screws or rubbers, the water may start dripping under the sink from connection pipes. 

Not only because of loose connection, the water may start leaking from under the sink because of rusted or wrecked water supply lines. So, you may need to change your old water line that is attached to the sink. You can replace kitchen sink by using proper tools like wrench to tighten the loose screws or O-rings. 

3) Damaged Gaskets

Damaged Gaskets

If you witness a kitchen sink leaking from the handle or your kitchen sink faucet, it might be because of a damaged or wrecked gasket. Don’t worry; it is really easy to identify the kitchen sink leak from your faucet or handle.

You can overcome this issue simply by replacing the old gasket with the new one.  You may also simply need to tighten the gasket if the condition of the gasket is good.

4) Damaged Washers and Rings

 Damaged Washers and Rings

If you are new to kitchen sink plumbing, learn about its ring or washers firstly to fix the kitchen sink leak issues. A ring is the main component to hold the kitchen sink faucet at its place. If your kitchen sink’s ring is broken or damaged, the water may start dripping out from your faucet or handle.

You can simply overcome this kitchen sink leak by replacing the old ring with a new one. Secondly, the wrecked washer is also a main cause of the kitchen sink leak. You can fix this issue simply by tightening the washer.

If the washer is completely damaged or broken, ensure to install the new washer to fix leaking pipe under the sink.

How to Fix a Leak Under Sink?

1) Assess Leakage Situation


Before learning how to fix a kitchen sink leak, you have to determine the situation of leakage you are facing under your sink. No doubt, it is not easy to locate the under the kitchen sink leak on time because of the sink cabinet or outlets.

If you suspect a leak under the kitchen sink, find out the main source or point from where the water is coming. You can check for the main cause by determining the amount of dampness around any specific area of your sink such as drain or base.

2) Identify the Type of Kitchen Sink Leak

 Identify the Type of Kitchen Sink Leak

If the under the kitchen sink leak is because of a pressurized supply line or pipe, you’ll clearly see the dampness around your kitchen sink cabinet or outlets. You cannot find the kitchen sink leaking at the drain until your sink is full of water.

The water will remain leaking from your drain pipes’ sides slowly or at the bottom of the drain. If the kitchen sink is because of the drain pipe, you’ll end up having a kitchen sink cabinet full of drainage water.

Therefore, you may need to check the entire areas of your kitchen sink especially inside the sink cabinet and around the connection pipes. The reason is that without detecting the under-kitchen sink leak, you cannot fix the issue accordingly.

3) Fix Leaky Faucet

Fix Leaky Faucet

There are rare chances for a kitchen sink leak because of a leaky faucet. But you still need to fix your leaky kitchen sink faucet if you suspect under the sink leakage. The best thing is that you can fix a leaky faucet quickly and easily simply by replacing the faucet.

You don’t need to replace the faucet in all cases. You can overcome the under the kitchen sink leak simply by tightening your kitchen sink faucet.

4) Seal Drain Strainer

Seal Drain Strainer.

If you have forgotten to seal, you’re the strainer while installing kitchen sink drain, ensure to seal it with putty as soon as possible or if you suspect kitchen sink leak. Most people also install a washer around the strainer as a sealer.

You may need to fix that washer or rubber to fix the kitchen sink leak.

5) Fix Leaky Drain Pipes

Even after sealing your kitchen sink drain, if you still suspect under the kitchen sink leak, you may need to fix your drain pipes. It doesn’t mean that you have to install new drain pipes. You can fix the leaking pipe under the sink simply by screwing your drain pipes tightly with a wrench.

Fix Leaky Drain Pipes

Additionally, you can also add putty around the drain flange to fix the leak under the kitchen sink. If you still notice the kitchen sink leak, you may need to change your damaged or broken drain pipe. It would be better to hire professional plumbers to fix or repair sink drain pipes because it is a complicated task.

However, you can replace a few parts of your sink drain pipes yourself to fix under the kitchen sink leak budget-friendly and timely. Hopefully, after following these steps, there will be no under the kitchen sink leakage.

Say Goodbye to Leakage

The easiest way to take care of the under the sink leakage is to maintain it on regular basis. Its recommended to inspect the sink on a monthly basis for any major leaks despite the cleaning ritual. Keep an eye out for any corroded or worn-out parts. If you find the leakage, follow these steps to ensure you can take quick action. 


  • Do Kitchen Sink Leakage Lead to Mold Growth?
    Even if the leak seems insignificant, mold and mildew can grow under the kitchen sink just within 24-48 hours of water damage. Once they do, they will pose a health risk for you.
  • Which is the Best Water Leak Sealant?
    To manage under the sink leakage you can use Epoxy putty, a two-part compound which can be mixed together. It is an ideal choice to seal the leakage under sink on metal and plastic pipes.
  • Can I apply Glue to Repair Kitchen Sink Leak?
    Yes, you can use repair epoxy, a viscous liquid used to repair pipe leaks on PVC. first, you will need to clean the damaged point and ensure water supply is cut off before applying it.
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Author: Amanda Arnold

Amanda has been working with ConstructionHow since 2021. Her experience spans over 5 years in the creative niche such as home decor and trends, landscaping, renovations, and custom architectural values. As a home designer expert, she has a keen eye for the latest home improvement trends with accurate facts that readers find impossible to ignore. Being invested in home-building trends is how she has gained her lucrative expertise exploring more to bring a positive ambiance for all homeowners (and even tenants!). Currently, she lives in a beautiful beach home, a source of fascination for her.