Discovering a leak under your sink can be a frustrating experience, often leading to water damage if not addressed promptly. Fortunately, most leaks in sink drain pipes are relatively simple to fix with a few basic tools and some know-how. Here’s a step-by-step guide on how to stop leaking pipes under a sink, whether it’s the drain pipes or the pipe connections.

How Do I Fix a Leak Under My Sink

Step-by-Step Guide to Fixing a Leaky Sink Drain Pipe

Step 1: Identify the Source of the Leak

  • Check Connections: Often, leaks are due to loose connections at the sink drain or the P-trap. While the water is running, check to see exactly where the water is coming out. This will help you identify whether it’s the pipes, the joints, or the seals that are leaking.
  • Type of Leak: Determine if the leak is at a joint or if it’s a crack in the pipe itself.

Step 2: Tighten the Slip Nuts

  • Tools Needed: You may need pliers or a wrench.
  • Procedure: If the leak is coming from a slip nut, try tightening it first. Slip nuts are the large nuts that screw on the connections around the trap. Turn them clockwise to tighten but be careful not to overtighten, as this can damage the nuts or threads.

Step 3: Replace the Washers or Gaskets

  • Identify the Right Size: Make sure you know the size and type of washer or gasket that fits your plumbing.
  • Replacing: If tightening the nuts doesn’t stop the leak, turn off the water supply, dismantle the connection, and replace any worn-out washers or rubber gaskets.

Step 4: Replace the P-Trap if Necessary

  • When to Replace: If the P-trap itself is damaged (cracked or corroded), it will need to be replaced.
  • Installation: Remove the old trap by unscrewing the slip nuts, remove it, and install a new one. Ensure all connections are tight and that new washers or gaskets are used if necessary.

Step 5: Use Teflon Tape

  • Securing Threads: For threaded pipe connections that continue to leak, wrap Teflon tape around the thread before screwing the nuts back on. This helps to create a watertight seal.

Step 6: Test Your Work

  • Check for Leaks: After making adjustments or replacements, turn on the water and check for leaks. Make sure everything is holding tight and that there are no new drips.

Step 7: Call a Professional Plumber

  • Complex Issues: If you’ve tried these steps and the leak persists, or if the damage seems extensive, it might be time to call a professional plumber. This is especially important to avoid potential water damage or complicated repairs that are beyond basic fixes.


Most leaks under the sink can be resolved with some DIY effort, saving you from potential damage and costly repairs. By following these steps, you can typically fix simple leaks in sink drain pipes and connections. However, don’t hesitate to call a professional leak repair plumber if the repair seems out of your depth. Ensuring your plumbing systems are functioning correctly is crucial for maintaining a safe and dry kitchen environment.

Don’t let a minor leak under your sink turn into a major headache! At Pinpoint Plumbing, we’re experts at swiftly and effectively resolving any plumbing issues, including those pesky leaks. Why not save yourself the stress and potential high costs of future repairs by getting it fixed right away? If your DIY efforts don’t pan out, or if you prefer the assurance of professional help, our skilled plumbers are ready to assist. We proudly serve Parramatta, Seven Hills, Blacktown, Quakers Hill, and other areas in Western Sydney. Call us today to ensure your plumbing is in top shape, and maintain a safe, dry kitchen environment with Pinpoint Plumbing.