7 easy steps to fix a leaking pipe under your sink

Drip, drip, drip… A leaking pipe underneath the sink is a common household issue, and it can range from a minor annoyance to a significant problem if left unchecked. But fear not, fixing it can be simpler than you think. Our expert plumbers at Outright Plumbing set the record straight with tips and tricks for fixing your leaking pipe. Whether you're a DIY enthusiast or a novice, here's a clear, step-by-step guide to help you handle the situation effectively.

It's always better to tackle a small leak before it becomes a flood. Early action saves time, money, and stress.

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What causes a leaking pipe?

First, let's unpack why a leak occurs. A leaking pipe under your sink could result from several factors: loose parts, such as the slip nuts holding the U-shaped pipe, worn-out rubber seals, or cracked plastic fittings. Pipes can weaken over time from general wear and tear. If you’ve experienced several drain clogs in your sink, it’s likely the result of excess pressure on your pipes. A leak should be resolved as soon as it comes to your attention to minimise damage.

Set on fixing a leaking pipe yourself? Here’s what you’ll need

Before diving into the repair, gather all the necessary tools and materials. This will make the process smoother and quicker.

Here’s a list of what you’ll need:

• Adjustable wrench (for metal connections only)
• Plumber's tape (Teflon tape for threaded metal joints)
• Bucket and towels or rags
• Replacement parts (like new rubber washers or gaskets)

You can find all these things at your local hardware store. Once you have your tools ready, the next steps will involve identifying the source of the leak, preparing the area, and then performing the actual repairs. Don't worry – we'll guide you through each stage.

Steps to follow to fix a leaking pipe underneath the sink

We know how overwhelming DIY jobs can be, especially when there’s a leak in your kitchen or bathroom. Take a deep breath; our plumbers have left clear instructions to make sure you're not left confused or at risk of making things worse. 

Step One: Turn Off the Water Supply

Before touching any tools, make sure you shut off your water supply to your sink, using the valves under your sink. Simply turn them clockwise.  If it’s a major leak, you may also need to shut off your main water supply, which is typically located outside. This helps avoid excess water interrupting your repairs or creating further damage.

Step two: Identify where the leak is coming from

You’ll want to pinpoint where the leak under your sink is coming from so that you use the right method of repair. Common culprits include the P-trap, supply lines, drain pipes, and faucet connections. Look for visible signs of water, like wet spots or pooling under the sink. Use a flashlight if necessary to inspect hard-to-see areas. Once you're certain where the leak originates, you're ready for the next steps.

Step three: Prepare your workspace

Next, prepare the area. Clear out any items stored under the sink to give yourself ample workspace. Place a bucket or an old rag underneath the leak to catch any drips. This will help keep your workspace dry and prevent further damage to the cabinet or floor.

Step Four: Disassemble and Inspect

Once you’ve identified where the leak is coming from, carefully unthread your connection. If your pipes are modern plastic, use your hands to disassemble them. A metal wrench can easily crack or strip plastic threads. For stainless steel supply lines or older metal traps, use your adjustable wrench. Take the pieces apart and check for worn, flattened, or split washers.

Step Five: Replace Damaged Components

Take your worn part or damaged pipe directly to the hardware store to find an exact match. Don't use tape or silicone to patch a cracked or split pipe fitting; these components are under structural stress and must be fully replaced to prevent future failure.

Step Six: Reassemble the connections

Fit your new washers correctly into the joints. The best method depends on what part you are fixing:

• Leaky P-Trap: Tighten the connections gently; you will need to either use your hands, if it's a plastic pipe, or a wrench, if you have older metal ones. If the leak persists, you may need to replace the washers or the entire P-trap.
• Supply Lines: Wrap Teflon tape clockwise around the metal threads, check for any loose connections, and tighten them down with your wrench. If the line itself is damaged, replacing it is the best option.
• Drain Pipes & Faucet Connections: Ensure the replacement gaskets, washers, or O-rings sit flush in their designated grooves before securing the drain hardware, and make sure everything is snug and leak-free.

Step seven: Run a water test 

Once all repairs are complete, turn the water supply back on and check for leaks. If you've done everything correctly, your sink should now be leak-free. Congratulations on a job well done!

A note on silicone

Silicone is commonly used in DIY jobs to reseal pipes because it is water-resistant. But before using it for your pipe repair, consider the type of leak you are experiencing and your pipe material. Furthermore, while silicone is an excellent gap-stop and temporary solution, it should not be used as a permanent fix; instead, you should use the methods outlined above. Make sure to prepare the area you are repairing so the silicone can bond effectively with your pipe. 

When to call in an expert plumber

If you can't fix the issue yourself, it’s time to contact Outright Plumbing Maintenance. Our team has decades of experience and will make sure you’ve fixed the actual leak that’s affecting your pipe. They’ll use industry-specific technology for leak detection, including acoustic sensors and thermal imaging to locate the source of your persistent leak.

Outright Plumbing is equipped to handle all your plumbing needs

We provide expert plumbers who specialise in repairing various leaking pipe issues, from burst pipes to faulty parts. Our professional services extend throughout the Bayside area, Mornington Peninsula & surrounding suburbs, ensuring timely and reliable solutions to keep your plumbing running smoothly. Don't let a leaking pipe disrupt your daily routine; expert help is just a call away.

 Small DIY fixes, such as repairing a leaking pipe under your sink, done right, can make all the difference. Acting fast can mean the difference between a small leak and severe water damage. Knowing how to first turn off your water meter and then fix a leak yourself is crucial for protecting your valuables and your property. 

If the problem runs deeper, you require the help of a professional. The team at Outright is here to make sure your water is running where it should and that your plumbing is working optimally.

Contact Outright Plumbing today to resolve your leaking pipe.

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