How to Clean Mildew from Grout

Co-authored by Dario Ragnolo

Last Updated: October 23, 2022 References

Mildew is a common problem in grout found in bathrooms. Regular cleaning should keep mildew mostly away, to the point it only needs to be cleaned with water. However, built up mildew should be targeted with a cleaning solution. There is no special formula to get rid of mildew. It simply takes a lot of scrubbing to get mildew and mold out of the grout between tiles.

Part 1

Part 1 of 3:

Choosing and Applying Your Cleaner

1
Try water alone for mild mildew. If you clean regularly, mildew is probably mild. A small film of mildew covering grout does not require special cleaners. For this mildew, stick to simply scrubbing water between the tiles. This should be enough to get rid of unwanted mildew.^{[1]
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- If mildew does not come out with water alone, you may need a stronger cleaner.
2
Use bleach for intense build up. Mildew that is built up over time requires a cleaner. Bleach is the best course of action to remove mildew.^{[2]
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Expert Source

Dario Ragnolo
House Cleaning Professional
Expert Interview. 13 August 2019.} You can buy bleach online or at a local department store.^{[3]
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- As bleach is dangerous if ingested, make sure to store it in a safe place away from children and pets.
- Wear gloves when handling bleach.
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3
Mix your cleaning solution. In a bucket, mix three parts water with one part bleach. The precise amount of bleach and water you need depends on how much mildew you're cleaning. Make sure to mix bleach in a well-ventilated area.^{[4]
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4
Spritz on your solution. Place your bleach solution is a spray bottle. Spritz a liberal amount of the solution over tiles, focusing on where you see built up mildew. Let the solution sit for about 15 minutes before continuing with the cleaning process.^{[5]
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Part 2

Part 2 of 3:

Scrubbing Out the Mildew

1
Scrub the mildew with a microfiber cloth. Use a microfiber cloth to scrub in between the towels to remove the mildew. It will take some force to scrub out mildew, especially set-in mildew, so scrub the cloth hard in areas where mildew appears.^{[6]
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- Remember to wear gloves if you're scrubbing in bleach.
2
Use a toothbrush for hard-to-reach places. If there is mildew built up in cracks and crevices, use a toothbrush.^{[7]
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Expert Source

Dario Ragnolo
House Cleaning Professional
Expert Interview. 13 August 2019.} A toothbrush is a great tool to get into corners and cracks where mildew lingers.^{[8]
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- Make sure to check cracks where grout is found for mildew. These areas are often neglected during cleaning, which can cause mildew to spread.
3
Give yourself enough time. There is no secret to removing mildew other than a lot of hard work. Mildew, especially if it's been built up over long periods of time, can sometimes be difficult to remove. Make sure to give yourself adequate time to fully remove the mildew. For grout that's heavily infested with mildew, the job may take over an hour to complete.^{[9]
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4
Use vinegar to remove water stains. Mildew can sometimes cause water deposits to build up on the walls surrounding grout and tiles. If you notice water deposits, saturate a paper towel with white vinegar. Place the towels over the water stains and leave them on for a few hours. Then, remove the paper towels and use a cloth or cleaning brush to scrub out the stains.^{[10]
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Part 3

Part 3 of 3:

Preventing Mildew

1
Ventilate your shower. A well-ventilated shower is key to preventing mildew to begin with.^{[11]
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Expert Source

Dario Ragnolo
House Cleaning Professional
Expert Interview. 13 August 2019.} If your shower has a fan, make sure to turn that on after getting out of the shower. It also helps to crack a window in your bathroom during the day.^{[12]
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2
Spray down your bathroom after showering. Keep a spray bottle in your bathroom filled with one part vinegar and one part water. Two to three times a week, use this mixture to spray down your shower. This will help prevent mildew from building up on the shower walls.^{[13]
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3
Clean your bathroom regularly. Mildew is hardest to remove when it's built up in grout between tiles. The best way to prevent the need for heavy cleaning is to clean your bathroom once a week. If you do a quick, mild cleaning weekly, you're unlikely to have to deal with heavy mildew removal in the future.^{[14]
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Expert Q&A

Question

What cleaners kill mildew?

Heather Isenberg
House Cleaning Professional
Heather Isenberg is a home cleaning expert and the Owner of The Tidy Maiden, a residential and commercial cleaning service company serving the San Jose and Los Angeles, California regions. Heather’s business The Tidy Maiden and Heather’s book The Automatic Bosslady were recently featured on CBS.

Heather Isenberg

House Cleaning Professional

Expert Answer

Try rubbing alcohol or Clorox Clean Up! Scrub the rubbing alcohol or Clorox Clean Up into the grout and mold. Spray the cleaner onto the grout and let it soak in for a minute or two before scrubbing the grout with a toothbrush or tile brush. However, some mold cannot be removed because of how deeply it's embedded in the grout. You may need to re-grout your shower.