3 Best Shower Caulks to Prevent Mildew And Mold Infections

The last thing you want infecting your home and particularly in your shower where you clean yourself is mildew and mold, yuk!

And it's in the shower they are more prevalent because of the moisture according to the Centres For Disease and Prevention.

And it's not like mildew and mold are harmless, far from it as according to WebMD they can cause serious health issues like allergies or asthma and make you sick!

So you should use the best shower caulks to prevent mildew and mold from growing in the first place.

But which caulk to choose to keep your home clean and yourself health? It's all revealed below...

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GE Sealants & Adhesives 281 Advanced Silicone 2 Kitchen & Bath Sealant, 2.8oz, White

One Of The Best Bathroom Caulk To Prevent Mold

This caulk by GE is a fantastic choice for someone looking for a durable and reliable sealant for use in their shower that has been proven time and time again to be effective.

This caulk is 100% waterproof, promising you that no matter how moist the inside of your bathroom gets, the silicone formula will not budge.

Talking of silicone, this caulk is 100% silicone and offers the most comprehensive protection.

It is not altered by fluctuations in temperatures and will hold up well in consistent high and low temperatures.

The mold and mildew protection that this caulk offers is next to nothing.

GE promises its users a whole 10 years of mold resistance! 

This places GEs product at the top of the game, considering most companies recommend that you recaulk after five years.

The caulk is flexible and easy to apply, adhering quickly to the surface.

Upon applying it, it takes only 30 minutes to be completely waterproof and promises low odor.

It is shrink proof, crack proof, and will not discolor or blemish metal finishes. 



  • It cannot be painted over so think wisely about whether you'll need to.


Flex Shot, 8 oz, Almond, Flexible Rubber Silicone Sealant, Waterproof Caulk, UV Resistant, No Caulk Gun Needed, Perfect for Kitchen, Bath, Showers, Sinks, Baseboards

One of the best shower sealants to prevent mold and mildew

This rubber sealant by Flex Shot has excellent sticking power and can caulk almost anything.

It is a great choice for your shower as it is watertight and works to resist mildew buildup.

It is easy to use and apply without the need for a caulking gun.

The instructions are easy to follow, and you get a perfect bead each time you apply. 

Application is free of muss and fuss as there is no drippage and no waste.

The tube gives you the perfect amount each time. It is available in white, clear, almond, and black to suit all bathroom needs (learn how to frame a bathroom mirror here).

It also expands and contracts with ease to fill whatever size hole or gap you need. 


  • Easy to use and apply as there's no drippage or waste. 

  • Holds up well over time so you won't have to re-do it any time soon.

  • Is smooth after application so looks nice and won't be rough to the touch.

  • No mess, so no cleaning up required.


  • Has a strong odor which will put some users off, open windows during and afterwards. 


Gorilla Waterproof Caulk & Seal 100% Silicone Sealant, White, 10oz Cartridge (Pack of 1)

Gorilla is another brand that is known for its great quality DIY and crafting equipment.

This sealant is flexible and versatile due to the fact that it is made from 100% silicone.

Silicone is one of the best choices when choosing a caulk that needs to be water resistant.

This particular product is the ‘White’ caulk, and it dries translucent white, making it a great choice for most bathrooms and showers.

It is ideal for filling in gaps and cracks between surfaces, both indoors and outdoors.

Its durability for the outdoors means that it translates well for in shower usage!

It resists the build up of mold and mildew, and will not crack or yellow over time 



  • The caulk has a very strong vinegar scent after applying. Whilst this does wear off after a while, it can be unpleasant for some


Red Devil 0405 Duraguard Kitchen & Bath Siliconized Acrylic Caulk, 5.5 oz, White

This caulk by Red Devil is a Siliconized Acrylic type, meaning it is not fully silicone but also has acrylic in there.

The result is a durable and adhesive formula that has been made water resistant by the addition of silicone.

Upon applying you will notice that there is excellent flexibility in the caulk, making it a great choice for areas in the shower.

The finish is smooth and satin, and when it is dry it is resistant to mold and mildew.

It is easy to clean up with just water, and Red Devil assures their users that the caulk is odorless. 



  • This caulk is not made from 100% silicone. Instead, it is siliconized, so it may not be as waterproof and flexible


Loctite Polyseamseal Tub & Tile Adhesive Caulk 5.5 Ounce

Loctite’s Polyseamseal Caulk is a great choice for those smaller jobs and touch ups.

Whilst it is not silicone, this latex formula still does a decent job of making gaps and holes watertight. 

When the caulk has cured, Loctite’s formula fights the growth of mold and mildew, as well as ensuring water will not impact it.

It adheres well to many surfaces such as ceramic, porcelain, enamel, and a number of plastics, among many other materials.

The caulk is flexible and durable when applied, and promises low odor application. 



  • This caulk is not made from silicone. Whilst latex does the job, it may not have the same quality of waterproofing and mold/mildew resistance as its silicone counterparts. 

Shower Caulk Buyers’ Guide

Mold and mildew resistant

Mold and mildew resistance is one of the most important factors to consider when buying a caulk for your shower. Any damp environment like a shower will be a breeding ground for the growth of mold and mildew.

When you are looking for a caulk to prevent mildew growth specifically, it is essential that you check for wording such as ‘mildew proof’, ‘mold-proof’, ‘mildew resistance’, and ‘mold resistance’.

If the caulk does not specify this, then it is not likely to be the right choice for your shower. 


Shower caulk should always be waterproof. Not all types of caulk will automatically be suitable for bathroom usage, especially when the caulk is going to be directly in the shower.

A non-waterproof caulk will not seal properly in a damp environment, and you will likely find that mold and mildew will grow much faster and be more destructive.

Generally, most bathroom caulk will be waterproof, but ensure to check that it specifies a waterproof seal. 


Typically there are two types of application methods for caulk. You can either get caulk that needs to be applied with a caulk gun, or caulk that gets squeezed out of the tube.

There is not one choice that is better than the other and it is likely to be a personal preference for what method you choose. It should be the method that you feel most comfortable using.

Caulk in a tube gets squeezed out and applied where you need it, for this reason, it is a great choice for those smaller jobs as you can just apply it directly where you need to.

Caulk guns are the better choice if you have some heavy-duty caulking and sealing that needs doing.

The gun applicator often allows for a precise aim, too, making it a great choice if you have a big job requiring caulking of intricate spaces between tiles. 


Generally, caulk comes in two colors, clear and white. There are also options to buy colored caulk, but these are a little more difficult to come by. Clear is a great choice because it does not show any color.

White is a good choice if you have white tiles or if you would like to have a white contrast with colored tiles. It is also worth noting the color of your shower.

Often shower bases are white, and so a clear or white caulk would blend more seamlessly than a colored or off-white caulk.

No color is better than the other, all of them will be as good as the other provided they meet the other requirements on our list.

However, you may find that the easiest choice will be clear or white as these are the most common ones and match the bathrooms of most people. 

How fast does it dry?

Consider how quickly your caulk dries after application. This is essential when using caulk in the bathroom because you don’t want to have to restrict bathroom usage and showering for a long period of time.

Look for a caulk that specifies that it has a quick drying time after it has been applied.

Most caulk that is made for bathroom and shower usage will likely have this feature but it is best to check just in case. 

Type of caulk

There are a number of different types of caulks to choose from that can be divided into groups. These are acrylic latex caulks, vinyl latex caulk, and silicone caulk.

Out of the three, the type that lends itself best to moist environments like the bathroom, and in particular, the shower, is silicone caulk.

This is because it is the most durable caulk to factors such as heat and moisture. It also tends to be the better choice when it comes to preventing the growth of mold and mildew.

Silicone caulk is very flexible and adheres well to whatever surface it is applied to.

This makes it the perfect choice to use in your shower to prevent mildew from growing.

It will resist the warm, wet conditions and hold up for a long period of time.

That being said, latex caulks are sometimes used in place of silicone with great success. Latex may not be as durable as silicone, but in smaller areas it proves helpful.

You will notice that our list contains one caulk made from latex. Through our research, we encountered many users who preferred this type of caulk for smaller areas and ‘holes’ in existing caulk. 

Frequently asked questions

How often should you caulk a shower?

The general rule of thumb when it comes to caulking is that it should last five years. That being said, it may last more or less depending on a number of factors.

If your caulk was not of high quality and did not have mold and mildew resistance, then you will likely find that you need to replace it more often.

A very high-quality caulk that has been used in a shower that is relatively free of excess moisture and dampness may last a little longer.

We do r not recommend leaving it any longer than five years, though, even if it does look in decent shape. This is to ensure that it is replaced and will protect your shower even more.

Not replacing it, even if it looks fine on the surface, may encourage mildew and mold to grow underneath the caulking and will eventually become more visible on the surface too. 

What happens if I don’t caulk my shower?

Linked to the previous question, the consequences of not caulking your shower can mean the growth of harmful mold and mildew will start to affect your bathroom.

This growth is more than an eyesore and nuisance. It can also cause health conditions if left for too long, such as respiratory issues and skin irritation.

Practically, it can also cause your shower base, tiles, and other parts of the shower to deteriorate faster, causing damp and moisture to build up in the cracks. 

How do you smooth caulk?

The best way to smooth out caulk, believe it or not, is to use your finger!

When the caulk has been applied, rub your finger with a small amount of water or rubbing alcohol, and run it all along the freshly caulked surface. The excess caulk will collect on your finger. 

You can then rub it off with a damp cotton rag, and continue until all the caulk is smooth, remembering to reapply the water or rubbing alcohol to your finger each time.

The rubbing alcohol is best used for silicone caulk. However, if you have a latex caulk then you should use water. Don’t forget to wash your hands well afterward. 

Can I caulk over old caulking?

No, you should not caulk over old caulk. The first reason is that it is likely to have trouble adhering properly to the old caulking, resulting in a messy application and a waste of your caulk.

This is especially true of silicone. Silicone will not stick to silicone, and so you should remove any old silicone caulk first before applying a new layer.

Secondly, caulking over old caulk can mean the potential for mold and mildew to develop.

This is because your old caulking may be harboring some hidden mold or mildew under there.

As annoying as it is, it is far better to remove the old caulking first, assess whether there is a need for a more intense mold or mildew removal, clean the surface down, and then go ahead and apply the new caulking.

Professionals will never re caulk over old caulk, and you shouldn’t either.

But what about caulking over new caulk?

How do you remove shower caulking?

Your best option for removing caulk is to take a sharp putty knife or utility knife and cut away at the strip.

Where you have made the incision you should then be able to grab onto the caulk and peel it away.

To this until all of the caulk has been removed. Some people may find this very annoying, but we think it’s pretty satisfying to peel away the caulk!

You can then use a scraper to remove any residue leftover. Clean down the surface and dry it well before reapplying any new layers. 

Final word

To conclude, if you are looking for the best caulk for your shower that will actively prevent mildew, then your best bet is to go for GE Advanced Silicone 2 Kitchen & Bath Sealant.

If this doesn't suit your needs, then any of the other products we have listed under our product guide will be perfect for your needs. If the products still don’t seem to work for you.

Then be sure to use our Buyers’ Guide and refer to the Frequently Asked Questions section to help you to buy the perfect shower caulk for your needs. Thank you for reading our article! 

Last update on 2024-06-13 / Affiliate links / Images from Amazon Product Advertising API