Bathroom Sink Drain Leaking Around Threads – Fixing Guide

Imagine you are in a hurry and brushing your teeth and suddenly find the bathroom sink drain leaking around threads. This could spoil your entire day. However, this is nothing uncommon and nothing to be worried about if you know how to fix this. The bathroom sink may leak for various reasons depending on the bathroom fittings.

Bathroom sink drain leaks mostly because of damaged thread and sometimes because of a faulty drain. Leaking could also happen if the nut in the sink is not in place. If the issue is with a damaged thread, it won’t take much effort to fix it. For other reasons, you may have to go for multiple steps.

The easiest solution to stop leaking is by hiring a professional plumber. But it is not unknown that a plumber would cost you a lot. So, fixing the leak yourself would be more convenient.

How to check what is causing the Leak?

If you want to fix the bathroom sink leaks, you need to be sure of what actually causes it. It is impossible to assume what is the actual reason without checking the parts one by one. People often mistakenly think bathroom sink drain leaking around threads means it is all about the thread. Go for the following steps to identify the real fact –

Check the Nut

This is the first point where you should start the inspection. Sometimes the drain may not misplace from the original position which makes the drain losse. As a result, water starts coming out through that small area.

To check the nut, use a set of wrench that could hold the nut tightly. Place the wrench on the drain nut and check if it is loose for any reason. Also check if the nut is spinning in place around the gasket, which could also result in leaking around threads.

Check the Thread

If you find that the nut is tight enough and keep holding the drain properly, check the thread. When the bathroom sink was installed, the plumber must have used thread tape to make it more secure. But after a long period of usages, the tape becomes loose and damaged. So, the sealing between the drain and the thread becomes loose. Water can easily leak from this area.

Check for Damages in the Drain

This is the interesting part. Even though you may notice the bathroom sink drain leaking around threads, the actual reason may be the damaged drain. There are mainly two parts in the drain that seal it from leakage – the rubber gasket and the drain seal.

If the drain seal is not working as it is supposed to do, leaking is common. Check the gasket and the sealing of the drain if everything is ok. Sometimes the sink cracks around drain and that also causes water leakage.

How to fix bathroom sink drain leaking around threads?

For each type of leaking issues, the fixing method will vary. Here are the things to do according to the type of leakage.

Tightening the Nut

Did you find the nut in the drain is not tight enough to secure it? Then hold the nut with an adjustable wrench and give it a gentle tight. However, don’t give too much pressure which could result in damage to the nut. Go slow and tighten the nut and check if the water is coming off from that particular area.

Turn the faucet on and look closely around the threads to identify if water leakage is happening. If the nut is damaged, must replace it.

Use New Thread Tape

If the thread in the sink drain is not secured, it will leak. A damaged thread can result in bathroom sink overflow leaking. To fix it, remove the nut from the drain with a wrench. Now remove the drain pipe and check if there is any plumber tape.

Remove the previous one and place new tape around the drain pipe as well as the bathroom sink. Attach the drain pipe and place the nut and it should work well.

Fixing the Drain

After a long time of usages, the drain pipe could cause leaking issues because of damages in it. A damaged drain can also cause bathroom sink overflow leaking. Check each part of the drain including the gasket to find the leakage area.

Replace the rubber gasket and place it by sealing the drain. Check the later part of this article for details of sealing a sink drain.

How to seal a bathroom sink drain?

To seal a bathroom sink drain, you need to remove the previous sealing from the drain. Remove the old sealant from the bottom of the drain flange. You may have to use a putty knife to cut the caulk. Remove everything that was holding the drain and sealing it.

Now apply silicone caulk around the drain hole to secure it. You may use plumber putty too at this point. Then drop the drain flange carefully and secure the drain to the sink.

How to fix sink drain leaking rubber gasket?

If the rubber gasket alone causes the leakage, it is easy to fix. Remove the center nut from the bathroom sink with an adjustable wrench. Remove the old rubber gasket from the drain and place a new one. Reattach the drain to the sink and it will stop leaking.

How to tighten nut under sink?

The nut under the sink is too loose to hold the drain? No problem! Hold the bottom of the nut with a plier so that it can’t move or spin in place. Use a wrench to give the nut a gentle tight. Move the nut clockwise to tighten it. Don’t give too much pressure to prevent damage.

Some Frequently Asked Questions

How do you fix a leaking bathroom sink underneath gasket?

To stop leaking the bathroom sink underneath the gasket, check the rubber sealing carefully. Probably it is damaged and causing a leak. Replace the rubber gasket and secure it to its position, that’s all you need to do.

Why is my bathroom sink leaking underneath?

In most cases the bathroom sink leaks underneath because of a damaged drain or a damaged nut. For both of these cases, must replace the previous one. Remove the drain from the sink and replace it with a new one.

How do you fix a leaky sink drain pipe?

If the drain pipe is leaking, there is no alternative to replacing it. However, in some cases, you may apply plumber putty as a temporary solution. But the best way is to replace the drain pipe with a new one. In that case, be sure that you know how to remove sink drain pipe coming out of wall.

Can plumbers putty stop leaks?

It depends on the type of leakage. All leakages can’t be stopped just by using plumber putty. But if it is about the drain sealing, plumber putty in the sealing area can stop leaking. For any damaged parts, the only putty is not enough.

Final Verdict

Now you know what to do when bathroom sink drain leaking around threads. Follow the guide carefully and you will be able to fix it yourself. Just be sure that you have all the essential tools. Be slow and find the accurate reason before you start fixing the sink leakage. If the condition is too complicated to handle yourself, we recommend consulting a plumber.

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