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How to Seal Bathtub Drain [5-Step Solution]

Having a bathtub is a sign of luxury and a form of self-care. But sometimes this at-home spa system becomes a nightmare. 

Plumbing issues in bathtubs have to be the grossest thing ever. Let alone if it involves the drainage system. But once you fix it all, it’s good to go.

How to seal the bathtub drain?

Start by scorning the chalk off the drain’s surroundings with a utility knife. Then, start cleaning the scraped portion for any remaining residue of chalk. After that, brush and wipe off any molds. Lastly, put a new caulk, preferably silicone to cover the drain.

This would be everything I will be discussing today. You should come to check it out. Let’s go!

4 Reasons Why Bathtub Drain Needs Sealing

If you tried the Ms.Monroe scene from The 7 years itch, I understand. I also understand that your bathtub drain is clogged due to all those bubbles in it. 

In such scenarios, you don’t even ask why the bathtub drain needs sealing. Let’s go check out some other reasons for bathtub sealing:

Reason 1: Water Damage

Water damage in the bathtub is unhealthy and gross. Without any drainage seal, the bathtub would become overflowed.

Now we don’t want a bathtub with an overflowed drain now, do we? This is why drainage is sealed. It’ll help to unclog stagnant water from drains.

Reason 2: Insulation

Sealing the drain excels the insulation in the bathtub. You wouldn’t have to keep filling the tub again and again with this. 

Insulation is necessary or else bathtubs will keep collecting bacteria. That could cause severe health issues.

Reason 3: Drainage Problem

Let’s talk about our main issue. Without a doubt, the drainage system will collapse if you don’t seal it.

Sealing the bathtub drain creates makes the bathtub more water-saving and less nature-threatening.

Reason 4: Safety

Imagine dropping your engagement ring in the drain while bathing. Scary, I know. The sealed drain will resist your favorite shiny stone going any far.

Also, it’s water-saving and the best way to ensure these small accidents don’t happen. 

As we have discussed our reasons, we will now go learn about the tools that go here. Let’s go:

Tools required to Seal the Drain

Now you can’t start a battle without your armors now, can you? That’s why here are some important tools that will be used in the process.

Utility Knife

Or you can use a putty knife if you want to be fancy. Either way, a good investment for future purposes.

Bathroom Cleaner

The most important thing is to clean up any mess that may develop. This is very effective for every DIY project like expanding foam under the bathtub or caulking the floor tile.

In this sense, here are some of my preferred bathroom cleaner brands:

Product 1
Product 2

Hope you like this just as much as I do. 

Silicone Caulk

The main ingredient to seal the drain. This one is considered the best way of sealing. It’s also the cheapest way too.

5 Ways of Sealing Bathtub Drain

Bathtub drain could be sealed in various ways. We have decided to use the easy tactic and use silicone caulk. Here is the detailed process:

Step 1: Scrape the Caulk

Due to too much moisture, the caulk around the bathtub gets damaged. To take it off, use a utility knife. Start by slowly scratching the damaged caulk.

Then remove the damaged portion. Do not put too much pressure or you’ll damage the drain itself.

Step 2: Wipe off the Residue

Use a very good bathroom cleaner to clean off the residual dirt. Using a moist, soapy cloth, wipe the drain.

To destroy mildew and microorganisms, use antibacterial soap. You wouldn’t have to worry about the unaligned bathtub drain anymore. 

This way, the drain surface would be leveled and evened out.

Step 3: Clean the Mold

We understand that if black mold is visible, you must act quickly. To remove the mold, start by scrubbing the area with an old toothbrush.

You may also try washing off the mold to get rid of it. Then, using a clean cloth, blot it dry. Latter is because to hold the caulk, the drain must be completely dry. 

It may seem disgusting, but it will be well worth it.

Step 4: Apply Silicone Caulk

Start with a sharp utility knife. Notch the tip of the waterproof silicone caulk, removing a quarter-inch of the tip. 

After that, at a 45-degree angle, make the incision. Now, keep caulking around the drain while holding it at an angle.

After you are done caulking, make sure you have made an even surface. Or I’m afraid you might have to redo your work.

Step 5: Let It Dry

But first, you need to do some extra work. Which is in a sink, wet your finger. And then, with that finger, smoothen out the caulk. 

Then scrape around the drain with the edge of an old credit card. Wipe away the excess with a dry towel.

Lastly, allow 24 hours for the sealant to set before utilizing the bathtub.

Final Thoughts

Now that we are here, I can say the bathtub is very high maintenance. Then again, as Hollywood’s famous symbol of sultriness, it deserves this attention. 

Remember to keep your bathtub drain clean. Dirt collecting in drains clogs it and becomes another headache. Unclog the drain after every bubble bath you take!

Jokes apart, hope this article cleared the pot of confusion for you. If so, then you’re good to go! If you can fix a dysfunctioning diverter stem, then sealing a bathtub drain should be as easy as cake.


Question: Can I use plumbers putty on the acrylic tub?

Answer: No, you can’t. Plumbers’ putty might react badly with the acrylic tub and ruin its texture. That’s why you shouldn’t use them.

Question: Can I turn my bathtub into a jacuzzi?

Answer: Yes, you can. Just add jacuzzi jets off amazon and you are good to go. It’s actually way cheaper than installing a new jacuzzi.

Question: Is it possible to spray foam under the bathtub?

Answer: Most definitely can. It’s perfect if you want to reduce coldness. But improper application might ruin the bathtub too.


If you read this far, then congratulations! You are a total pro on how to seal the bathtub drain. At least I hope so.

But, if you couldn’t do the job, that’s alright as well. Not everybody has to do everything. Just call a professional for help.