Q&A / 

Removing Mildew from Grout

DEAR TIM: It is a long, long story but the bottom line is that my ceramic tile shower is a mess. There is mildew everywhere and other really tough stains that are nearly impossible to remove. Is there a way to make the white grout look like new? It seems that the mildew has penetrated deeply into the grout. What can I do to restore the shower to its original condition? What can I do to prevent this from happening again? Molly S., Orangeburg, SC

DEAR MOLLY: Six weeks ago a friend of mine had the same problem. One day while we were at the swimming pool he said he tried many off the shelf cleaners and products to clean his tile shower. He was not satisfied with the results and was ready to tear out the tile and grout and start over. I told him that he had the necessary cleaning products in his house the entire time and had overlooked them. When I told him the solution to his problem, he couldn't believe it. Two weeks ago he said his shower looks fabulous. Ah, another satisfied customer!

To restore your ceramic tile shower to near perfect condition, you are going to need several things. Get a new scrub brush that has stiff nylon or plastic bristles, a roll of paper towels, a gallon of chlorine bleach, a gallon of white vinegar, a spray bathroom cleaner or ultra mild abrasive cleaner, and your birthday suit. The stains and dirt have taken months to accumulate. Don't think you are going to complete this job in 30 minutes or less. The entire process is going to take place over a period of hours and possibly several days.

The first thing to do is to use the scrub brush to remove as much mildew, dirt, soap film etc. as possible from the tile and grout. Get into the shower and scrub well using lots of water and plenty of cleaner. Rinse often and do whatever is necessary to make the tile surfaces shine like a mirror. Don't worry that the grout is still gray with deeply embedded mildew. We will deal with that shortly.

After this cleaning process, you will probably have some dull stains that won't budge. These are very likely hard water deposits. You will remove those using some paper towels and white vinegar. Saturate some paper towels with the vinegar and place them over the hard water stains. Do this on the floor and any vertical surfaces. The wet paper towels will readily cling to vertical surfaces. Vinegar is a very mild acid and it works slowly but efficiently to dissolve the alkaline water deposits.

Get dressed or put on your robe and go relax for a while. Stop back every hour to make sure the towels are still wet with vinegar. Pull away a towel and scrub the deposits. They may completely wash away. If they do not, pour fresh vinegar on the towels to continue the cleansing chemical reaction. Heavy deposits can take up to eight hours or so to completely melt away. The trick is to keep fresh vinegar on the towels.

Restore the "clean" to your grout. Just go to CLEANGROUTNOW to see the beautiful, quick results.

Once you have all of the hard water deposits removed, clean the shower again to remove all traces of vinegar. It is now time to attack any residual mildew that has stained the grout. You are going to use the pure chlorine bleach and the remaining paper towels to accomplish this task. Saturate as many towels as necessary and put these in contact with the mildew stained grout. It can take hours and possibly days to bleach out all of the mildew in the grout. Be careful not to splash the chlorine bleach in your eyes or on any fabrics or carpets. It can harm you and it removes color from dyed fabrics.

If you are allergic to chlorine bleach or the chlorine fumes bother you, use oxygen bleach to remove mildew. You use the same techniques as described above, it just might take a little longer. Oxygen bleach is color and fabric safe. It is also excellent for people who have septic systems. Chlorine bleach that escapes from the tub or shower into the drain system can kill beneficial bacteria in the septic tank. Oxygen bleach actually helps this bacteria!

To prevent the staining problem in your shower, it helps to understand mildew. It is an organism that requires food and water to live. Showers and bath areas provide the moisture and you provide the food every time you use soap, shampoo, cream rinse, etc. Even the dirt and oils you wash from your skin and hair are food for mildew. If you minimize or eliminate the food and water, you can eliminate the mildew.

I feel the best way to defeat mildew is to clean the shower every two weeks. Every day after you have showered use a plastic cup to pour clean water down the sides of the tile. Then use a squeegee to quickly wipe down the tiles directing as much water as possible to the shower drain. These two simple steps will remove a huge amount of food and water from the shower each day. When you get ready to leave the bathroom, open the shower curtain or shower door. Keep the bathroom door open as well. You want as much air to circulate in the shower as possible. This will dry all bath surfaces quickly and rob any microscopic mildew spores of water.

Message from Tim:

Years ago while researching a column about cleaning decks, I discovered the wonders of Oxygen Bleach. It is perhaps the 'greenest' cleaner I know of as it uses oxygen ions to break apart stains, dirt and odor molecules. There are no harsh chemicals, and it works on just about anything that is water washable.

I decided to create my own special blend using ingredients made in the USA. In fact, the raw materials in the active ingredient are food-grade quality registered with the FDA. I call my product Stain Solver. I urge you to use it to help clean your ceramic tile and grout. You will be amazed at the results!

Companion Articles:   Bathroom Mildew Removal, Oxygen Bleach Tile CleanerCeramic Tile Cleaner Products

Column 284


23 Responses to Removing Mildew from Grout

  1. Hi Tim, I have a problem with orangy stain in my grout which is white on white tile, and some areas have a dark stain. I assume it is shampoo build up and mold as I dont often use soap, but sometimes body washes. I am only able to clean a tiny portion of the shower stall at a time due to untratable asthma. I sprayed a very sm area today with bathroom and tile cleaner, not even H20 bleach, and couldnt breath. I had to stop right there. I sometimes will spray a soln of 95:5 H20 to O2 bleach then go back and run the shower but after reading your article I understand why that is not working...its not staying wet long enough to dissolve any matter. AHHH. Thank you.
    given that I have multiple chemical sensitivities etc I wonder if using the hand held unit form my floor steamer would be a good solution for me, using just plain water. What do you think? Thank you for offering this to people; you are a wealth of knowledge and are very inspirational.

  2. Tim, once the shower is cleaned, how can a person keep the mildew from returning? We live in the damp northwest and what with the humidity and people taking showers at different times of day, the surfaces do not seem to ever really dry out.

  3. I tried the bleach on the paper towel method yesterday and was so surprised this morning. It removed all of the mildew in less than 24 hours. Thank you!!!

  4. Thank you for this article! My main issue was stained grout from where loofahs etc hang in the shower - I would never have thought of paper towels and now I can finally clean my shower properly 🙂

  5. remind people to thoroughly clean the vinegar off before applying bleach as those two chemicals make another chemical and it is noxious!

  6. Thank you, Tim. 🙂 Having real trouble with my shower tiles in this way. The mildew is rock-hard and nothing will bring it up. I'm going to do what you said. Bleach and vinegar sounds good to be!

  7. Thanks Tim. Your article saved us a few thousand dollars. Do you recommend sealing the grout once the stains have been removed?

  8. Going to try the bleach idea. I moved into an apartment on campus, and the people who lived here before us never cleaned the shower properly. My roommate and I spend hours scrubbing, but nothing worked. Hopefully this will.

  9. I saw mold appearing on/in my grout. I sprayed with Tilex mildew root Penetrator, let it sit for a while, took a brush, scrubbed, rinsed, but no change in the mold or mildew. Actually the grout was beginning to break up so I purchased a clear calking and spread it thinking it would take care of it, but NOPE.
    Now what do I do?

  10. I am really anxious to get the tile and grout clean in our new rental, but my tile is over an enamel tub, which is new for me. From my research, I understand that bleach and vinegar will damage an enamel tub. Additionally, I have problems with conventional bathroom cleaners (Tilex) leaving rust-colored stains when they drip down off the tile.

    I'm having a hard time coming up with a starting point. Help?

  11. yes!!! this actually worked! I was convinced the mold in my grout would never come out but after the vinegar and the bleach it's completely gone! I wish I could share before and after pics! it's like magic! thank you so much for the info!!! 🙂

  12. Tried this and it totally work. I've been struggling with black mold on the tile for a year and this finally got rid of it. It took almost 12 hrs with the vinegar and 24 with the bleach!

    However, I seem to have a secondary (less concerning since it's cosmetic but stil...) problem - the tiles have a white haze. They look find when they are wet but they dry white. I've scrubbed with my nylon brush but nothing. I tried a post vinegar round but that seems to have made it worse - seems like something worn off on top (not a film.) Any thoughts on what happened and how I can fix it?

    I'm mostly thrilled that we aren't facing the health issues related to the mold but it would be a complete win if I can get my tile looking pretty again.


  13. I clean houses, basic cleaning only. One of my houses that I've been cleaning for about 3 years was talking about having their tile shower replaced. I followed your directions and although it took about 5 hours total, it worked awesomely. I saved them from having to pay to replace theirs (yeah, it worked that well). Thanks for the info!

  14. Hi tim

    Looking forward to trying this. I bought a place where there's lots of mold in the grout. But I was curious your opinion before trying, the grout the previous owner used that's molding is very coarse and sand like. Additionally, in some places the grout is wearing away, doesn't seem to be sealed contributing the mold, and isn't all flush with the tile. Do you recommend I try your cleaning steps or do I need to remove the grout and redo it entirely?

  15. This worked like a charm! I was amazed at the difference in my shower stall. I wish I had taken before and after photos to share. So glad I came across this article!

  16. Hi Tim,

    As this is quite an old post I'm not sure if you're keeping up on it but I figure it's worth a shot. I have a shower with brown grout (intentionally), not white. It's starting to get black in the corners and I'm wondering if the bleach with make the grout white, which I do not want. Also, the floor is river rock, will this be an issue if bleach or vinegar is used on it?


  17. Why mold cause sever health problems just because of the people not take any action when they found mold in their house and after that the mold increases in growth and cause severe health issues to homeowners. They spend their day in that environment which is highly affected with the Toxic black mold which can also harmful to your health and cause a permanent damage. Homeowners never realize the affter effects of that black mold until they practically go through it. Toxic black mold cause problems such as mental disability, damaging internal organs, and sometimes a purpose of death. You can just have a quick checklist to remove Black mold without killing the environment as i have found both of the articles helpful for me. http://www.floodaz.com/how-to-remove-black-mold-without-killing-the-environment/

Leave a Reply

Your email address will not be published. Required fields are marked *