How To Get Rid Of Mould On Caulk or Silicone Joints & Corners

Once mould starts growing on caulk or silicone joints and corners in your bathroom, it can be quite difficult to clean. You can scrub away for hours using bathroom cleaners and not really make much progress. We’ve found a solution that works well to remove mould on caulk and doesn’t require any scrubbing, you probably even have most of what you need in your home already.

If you’ve got hard water stains in your basin, bath or toilet, you can make an Epsom salt scrub to remove it.

What You Need To Clean Your Caulk Joints

  • 1/4 Cup of Household Bleach – Buy Here
  • 1/2 Cup of Baking Soda – Buy Here
  • An Old Toothbrush
  • A Disposable Cup or Container – Buy Here

How To Remove The Mould On Caulk Joints

You’ll need to mix the baking soda together with the bleach in your container. Start by adding a small amount of each and work until you run out of one of the ingredients. The mixture should form a paste which is quite thick and not drip off of the toothbrush, similar to toothpaste. The quantities are approximate and may need to be adjusted a little depending on how thick your bleach is.

Once you’ve got your thick bleach and baking soda paste, head into your bathroom and open up a window or turn on the extractor fan to get some fresh air flowing through the room. The mixture has a strong smell when you start spreading it out. You might also want to wear rubber gloves so that you don’t get it on your hands, undiluted bleach can be quite harsh on your skin and may cause burns or an allergic reaction.

Use the toothbrush to gently brush the mixture onto the mouldy spots, completely covering them. Make sure that the paste is thick enough to be held in place for an hour or so, it shouldn’t run down or drip off of the joint but should also completely cover the mould and shouldn’t be crumbly.

Note: You might want to test the mixture in a small hidden area to make sure that it doesn’t cause discolouration of your tiles.

Once you’ve brushed the mixture onto all of the mouldy spots, you just need to wait for the bleach to do the work. This usually takes about an hour, depending on how bad the mould is. It’s a good idea to check on the paste halfway through to make sure that it’s still in place.

After an hour, use some warm water and the toothbrush to wash the paste away. Make sure that it doesn’t drip onto your floor or bathmat or towels in the process as it may discolour them.

Once you’re done, the mould should be gone, or at least significantly lighter. Sometimes stubborn mould requires a second treatment.

Have you tried this method to clean the mould from your caulk or silicone joints and corners? Let us know what worked for you in the comments section below.

Michael Klements
Michael Klements
Hi, my name is Michael and I started this blog in 2016 to share my DIY journey with you. I love tinkering with electronics, making, fixing, and building - I'm always looking for new projects and exciting DIY ideas. If you do too, grab a cup of coffee and settle in, I'm happy to have you here.


  1. Once mold does start growing, cleaning becomes an absolute nightmare. I’ve had such significant troubles with the cleaning process. I can’t even begin to tell. Make sure that you have steps in place to protect against mold.


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