Why Does My Bathroom Caulk Get Moldy and How to Deal with It?

Last updated:

Bathrooms are often a relaxing and happy place. There is nothing like a long shower after a hectic day. But, what’s that in the corner of the shower? Mold!

Mold on the bathroom caulk is not pleasant! How does this mold occur?

Key Takeaways
  • Your bathroom caulk gets moldy because of the mold spores that fell on them and develop over time. To get rid of mold on your bathroom caulk, often all you need to do is use bleach, vinegar, or hydrogen peroxide to wipe it off.
  • In some situations you will have to scrap off and remove the old caulk and replace it. There are some useful tools available to do this.

Why Does Your Bathroom Caulk Get Moldy?

Mold is a type of fungi that grows anywhere it can. It exists as a multicellular filament that grows on a unique structure called hyphae. 

What makes mold so annoying is its ability to reproduce quickly. This swift spawning ability is primarily because of their anatomy. As a result, mold reproduces by spreading its spores. 

These spores are carried in the air and can move to great distances. So, let’s say your bathroom didn’t already have any mold on it when the caulk was applied, which is virtually impossible. There is an excellent chance that mold that settled on your body in the day will fall from you and settle on the caulk.

Also, because water keeps splashing when you bathe, there’ll be enough moisture on the caulk, which is a good condition for the mold.

What will the mold feed on to grow?

Mold feeds on organic matter. This means that it eats anything that was once a living thing. Unfortunately, in your bathroom, there could be a lot of these things. 

Ranging from dead skin cells to bits of cardboard from your soap’s packaging, there’s a lot of food for the mold to grow on. So it will take a while for them to grow and spread. But if you don’t clean your bathroom regularly, the growth rate will be even faster.

You may clean your bathroom very often but still notice mold growth. The reason could be because you don’t take time to scrub the caulk when you clean. And so, the mold will be left relatively unbothered and will keep spreading.

Why Doesn’t Heat from Your Shower Kill the Mold?

It’s pretty rational for you to think that the hot steam and water you expose the mold to will kill them off. Well, molds are quite stubborn microorganisms. They are known to withstand temperatures up to 120 degrees Fahrenheit! That’s 48 degrees Celsius!

Unfortunately, the average heat of your shower is about 105 degrees Fahrenheit. One hundred twenty degrees will scald your skin, and would you honestly bathe with water that hot to have a chance to kill mold? Of course not.

So, your bathroom gives the mold near-perfect situations to thrive. And the species of mold that grows in your bathroom is specially adapted to grow there. As a result, they are much more resistant to adverse conditions than typical bread mold. 

How to Get Rid of Mold on Your Bathroom Caulk

Now let’s get to the crux of the matter. How exactly do you get rid of the mold that grows in your bathroom?

Well, three primary methods are all dependent on wiping or scrubbing. To effectively eradicate bathroom caulk mold, you could either use:

  • Vinegar
  • Bleach, or
  • Hydrogen peroxide

To get rid of bathroom mold using Vinegar, take the following steps:

  1. Get all the materials you need ready. You’ll need a clean sponge, a clean toothbrush, some white vinegar, and a bowl.
  2. Pour some white vinegar into a bowl and dip the clean toothbrush into the liquid.
  3. Use the toothbrush to scrub the areas with mold well.
  4. Keep doing this until the mold patches are no longer visible.
  5. Dip the sponge into the vinegar bowl, and with the liquid you absorb, wipe the tiles in your bathroom. Doing this will kill off any mold on them that would migrate to the caulk.
  6. Allow the vinegar to stay on these surfaces for about 30 minutes.
  7. Rinse off the vinegar with water and a clean rag.

To get rid of bathroom mold using Bleach, take the following steps:

  1. Make sure you have all the materials you’ll need ready. For example, you’ll need an empty spray bottle, some bleach, a clean toothbrush, a bowl of water, and a sponge.
  2. Pour some bleach into the spray bottle. 
  3. Spray some bleach onto the corners and space filled with caulk where you notice mold growing and leave for about an hour.
  4. Use the toothbrush to scrub those areas you sprayed and keep spraying as you’re scrubbing for a better effect.
  5. Keep scrubbing off the mold until you’re satisfied with the cleanness
  6. Spray bleach onto the sponge until it’s soaked enough for use. 
  7. Use the sponge to wipe the tiles on the wall, eliminating any mold on them that may have moved to the caulk.
  8. Using a clean sponge and clean water, wipe off the bleach from these surfaces.

To get rid of bathroom mold using Hydrogen Peroxide, take the following steps:

  1. Get all the materials you’ll need; these materials include an empty spray bottle, some hydrogen peroxide, a clean toothbrush, clean water, and a sponge.
  2. Pour some of the hydrogen peroxides into the empty spray bottle. Do this swiftly and neatly as hydrogen peroxide evaporates very quickly.
  3. Spray the hydrogen peroxide on the moldy caulk and scrub it off with the clean toothbrush. Repeat this process on all the areas with mold.
  4. Spray some hydrogen peroxide on the sponge and use it to wipe off the bathroom tiles to kill off mold that you can’t see. 
  5. Wipe the hydrogen peroxide off with clean water and a sponge after 30 minutes.

These are highly effective methods to get rid of mold in your bathroom.

To prevent further growth, it would be best if you keep doing this regularly. Doing this will kill off the mold continually and make the caulk an unsuitable environment for their growth.

If all these methods do not remove the mold it may be time to replace the caulk. You can purchase special tools to scrap up the existing caulk and then find a suitable bathroom silicon to reseal the join.