I am wondering if there is a coating, seal, paint or whatever product that I can apply to the grout between shower tiles to prevent mold?

The junction between the shower tiles of my shower pit has black mold formed. See this pictureenter image description here I am using a squeegee to clean the tiles after each shower, but it only slows down the mold formation.

Is there a product (preferably not too expensive) that I can apply to the junction to prevent mold formation?

1 Answer 1


Grout is porous which allows water to sit and grow mold. You need to use a grout sealing product.

Example: https://www.homedepot.com/p/Custom-Building-Products-Aqua-Mix-Sealer-s-Choice-Gold-24-oz-Penetrating-Sealer-AMSC24Z/202907686

After cleaning your grout, you can use a product that will soak in to the grout and seal it from water entering. You should do this about once a year to prevent mold.

Use a foam brush and/or grout sealer applicator to apply it on cleaned grout. Do a second coat within 30 minutes to an hour or so (follow the product directions). Foam brushes are easer on wall grout IMHO.

To test after sealer dries, take a drop of water and put it on the grout. If it soaks it in, you need more sealer. If it beads on top or rolls past it, your good to go!

Sealing grout is an easy win in home care! Make sure you have good ventilation when using these products as they have a lot of VOCs!

  • Oh Grout seal, that seems to be the silver bullet I was looking for. Does it matter what type of grout it was there before? And by cleaning grout, do you mean that I have to get rid of the existing mold and let it dry? Thanks
    – Chen
    Commented Aug 11, 2020 at 2:47
  • 1
    You want to get rid of the existing mold because it will be held in there by the sealant. There are a variety of options to remove mold, though I would recommend something that soaks in and gets to the root of the mold like a mold removing product. I've read about peroxide as well, but haven't tried that one yet. Whatever you do, definitely let it dry before sealing it.
    – face.
    Commented Aug 11, 2020 at 3:15
  • 2
    There are other products that attempt to remove mold stains, but this is a good products to start with: homedepot.com/p/Concrobium-32-oz-Mold-Control-025326/100654126
    – face.
    Commented Aug 11, 2020 at 3:21

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