How To Seal The Sink Basin Opening

What to do with Leaking under sink– Leaking in your bathroom sink can be a pain to resolve this usually happens when you install a new sink basin waste system and usually there is uneven gap or unsealed gap under the sink and the basin waste unit. Typically when you buy a new one it comes with a rubber flat seal and a thin plastic washer but this is insufficient for most basins. I will show you quick permanent fix to stop your leaking under the basin.

Ideal method to stop leaking basin in Bathroom

Plumbsure Plastic & Rubber Basin SealerTo fix a small leak around the sink neck and gasket purchase a plumbsure plastic & rubber basin sealer or also known as a vanity bowl sealer you can pick one up at your local hardware store for a few dollars. Vanity bowl sealer’s are very easy to install as no sealant is required but you can use plumbers putty around the gasket if you want. These are a great time saver especially when you have little access under your bathroom sink unit.



Step 1 – Basin & vanity bowl sealer fitting instructions

Buy a basin & vanity bowl sealer it comes with everything you need other than your plastic nut this is provided to you when you buy your basin waste unit or just use the one that was previously used. The great thing about these, are there is no need for sealer so it’s a mess free job !

basin and vanity bowl sealer set up

Step 2 – Tighten

Super easy place you’re the sealer you just purchased under the basin and begin to tighten the large nut. This needs to be firmly tight to ensure a watertight and leak free bathroom basin. This will get very hard to tighten as you get closer but it’s absolutely essential that this is as tight as you can achieve. Once it’s on tight you will have a leak free bathroom vanity bowl so it’s worth the effort. If you need some great professional tips on installing bathroom faucets we have a detailed article covering the step-by-step process.

basin and vanity bowl sealer finished

Watch this short video below to see how easy it is to install the vanity bowl sealer in less than 30 mins you will have no leaks from under your basin unit. This really is a huge time saver and will ensure you have it leak free for many years to come. Feel free to comment and share this article and video to help others who have the same problem.

Method 2, How to resolve a leak under your bathroom basin

New leak free basin

The first image you can see the standard components you get when you buy a basin waste unit, I had an additional rubber basin waste seal in my garage this will ensure a thought seal and eliminate your under sink leak.

typical components

Step 1 – Clean

Clean the sink under and on top as much as possible and dry. you want to work with a clean and dry surface so your sealer has a clean and dry surface area to grab.

clean and dry

Step 2 – Prepare sealer

Add sealant to your basin waste and your new rubber basin waste seal then place your basin waste throw the top and slip on the new rubber basin seal from the bottom and push as high as possible to seal the gap.

silicon selant

Step 3 – washers

Place the other rubber washer and then your clear plastic non grip washer and begin to tighten.

add washers final step

Step 4 – secure

Make sure you have given the nut a good tight seal lock by securing the nut and insuring all the washers are in place.

clean and dry

Step 5 – dry

Give the sealant sufficient time to seal a good few hours 2-4 hours should do the trick then test for any leaking under the sink.


Other possible causes to leaks under the bathroom basin Sink

First check your S bends for any leaks if leaks are there then use PTFE tape a quick and simple job don’t over tighten the nuts they are supposed to be hand tight over tightening will open gaps in the threads. Using PTFE tape will give you a leak free S bend on your plastic waste pipes under your bathroom sink. For other great leak free tips and advise on home pluming find all out great articles on our home page.

S bend sealed with ptfe tape

Now you can enjoy a leak free bathroom basin.


Please feel free check out our other great articles on bathroom pluming to comment below and hope this has been a clear and informative article to stop water leaking from under your bathroom basin.