Removing Mildew from Grout

Maybe this works, but the fumes were overpowering even with ventilation. I would hesitate to recommend this.

Mark and Peg,
You are so right. The fumes can be really bad. But with repeated applications, it works. If you don't want fumes, consider Oxygen Bleach. There are no fumes at all.

Should I be concerned about the bleach affecting the color of my grout. It is a light tan (linen) color.

Thanks.

Matt,
You should to a small degree. I would test a small area.

Thanks Tim. Your paper towel trick was ingenious. After scrubbing for hours at deeply embedded mildew in my bathtub's grout, only a bit came out. I just tried paper towel soaked in bleach, and after twenty minutes 90% of it is already gone. Happiness!! :) :)

Should I be concerned that using bleach will break down the surface of my tiles?

Jessica,
Chlorine bleach will not harm glazed tile.

Will the bleach harm natural stone (travertine)? Thanks for the info.

Will this work on mildew that has grown on the bathroom floor behind a toilet. Is there something I can do about a toilet sweating and dripping on the floor.

Antresia,
Toilet sweating can be prevented by installing toilet tank liners. I got some from Home Depot for around $15 (in canada so your prices might be different). The package comes with thin sheets of styrofoam, glue(waterproof after 24-48 hours to dry)and instructions on how to cut it to fit the inside of your tank. It's also handy to have rubber gloves for cleaning the inside of the tank, a small cup & sponge to get excess water out, and a blow dryer to dry out the tank. As well a marker, long ruler, and sharp utility knife.
:) Cheers

Thank you so much Tim! You saved me from having to recaulk my bathtub. One question: I've read some places online that bleach doesn't kill the mold and that it will eventually come back. If I follow your tips on how to prevent mold, should I have any more problems? Do I need to treat my bathtub with anything else to prevent future mold outbreaks?

Tim, I had not thought about hard water deposits, and think that this is what is all over my glass shower door -- will the vinegar trick be the best on a glass surface too?
Thanks!

Along with the gray grout comment up there....i have a brown grout, would I be best off to just start off with the oxygen bleach?
Also, I am a brand new homeowner and I am not sure that the grout is correct in my bathroom. It is super rough, and seems like there should be some sort of caulking instead inside/around the bathtub. (Maybe I just think that because that is how all my bathtubs were growing up) Is this something I should consider, or even apply OVER the grout?? I'm very confused.... so any advice would be greatly appreciated

I have a new shower stall that has tile with a beige grout. There is a red stain that stains the grout in a couple of places. A friend told me it is a bacteria called serratia marcessans that is staining the grout. The builder of our new house has removed the grout and re-grouted and re-sealed it twice, but the red keeps coming back. Any suggestions?

Thank you so much for your great advice! Questions... I thought I was going to have to regrout. I tried using my Clorox Oxy Clean spray and didn't have much luck today. However, tomorrow, I am going to buy Bar Keeper's friend (is this okay to use, it's the most effective cleaner I have used besides the Lysol Mildew remover), vinegar, bleach. Someone mentioned the terrible smell w/ the bleach, could I use a Bleach gel pen instead? It's less messy and go directly on the grout. Will I have to put a towel over the gel as well if it's okay to use?

Thanks so much for your help!!!!

Hi Tim,

Thanks for the great information. Is it possible to use distilled white vinegar to remove mildew from grout intead of bleach?

Hi Tim,
I love your site.
I have a question. I'm at the end of my rope with this mildew issue. I've used bleach, bleach pens vinegar (not the precise way that you outline above) and I've gotten no results. Before I embark on this latest version I just wanted to ask you what if it appears that the mildew is actually growing UNDER the caulking between the tiles? Will this method work owr will I have to remove the caulking and start from scratch. Your insight is most appreciated.
Best,
Marla

Would peroxide work in place of bleach? I Market clean air and water products and I have just about got chlorine bleach out of my house.

Thanks for the great tip. My shower is only about two years old and was kept clean so it was a fairly light job, and with just a little scrubbing I was able to get all the soap film and mildew out after letting the vinegar soak for about 6 hours - didn't even have to use the bleach.

What was your answer to will bleach harm natural stone? My shower is natural stone and the grout and caulking have mildew. I am afraid to clean with bleach and do not know what to use. Please advise. Thanks

If Mark & Peg above got overpowering fumes, they may not have adequately rinsed between the vinegar and the chlorine bleach. Mixing bleach and vinegar will release chlorine gas, which you really don't want. The instructions are good - remove all traces of vinegar. Rinse a lot!

We've followed your instructions using the saturated paper towels. How long should the grout air dry before we recaulk? What kind of caulk do you recommend for a shower where the wall tile and the floor tile come together?
Thank you.

Hi is there any risk of the bleach staining painted pattern on blue tiles. Also, the previous owner appears to have run a line of solastic down the grout in the shower corner. Not sure why they would have done this? will the mould come out of the solastic?

Antresia,
I also have the same problem as you, butl I think you have it worse. I also sweat on the toilet but mine never comes to dripping wet on the floor!!

Maybe I have better ventilation.

Thanks for this advice Tim, it worked a treat after about 3 hours which I spent having a quiet couple of beers.

Beats re-grouting any day (which is what my wife thinks I did!)

Thanks again,

al

Just looking over this... make sure you follow directions and thoroughly remove all traces of vinegar from the walls before you move onto bleaching. If you can still smell vinegar, there's too much. If bleach and vinegar, ammonia or another acid mix, they produce chlorine gas, which can be permanently harmful or lethal, depending on the amount you inhale.

Will the bleach harm natural stone (travertine)? Thanks for the info.

Tim, it worked like a charm! My grout looks as good as the day it was laid!!!

One thing I'd add to the comments is that there may be an easier way to paper the wall. I think I'd try taping the roll of towels to the top of the shower and rolling them down the wall, and then wetting them. It would be faster than putting the towels on one at a time. That took me some time, and of course I didn't think of the "better way" until I was finished!

Great tip, great results! Truly amazing.

I want to vouch for the effectiveness of this technique. The only issue is the fumes from the bleach. Even with adequate ventilation it can seem overpowering so you may have to work in sections or use oxygen bleach as Tim mentioned. Leaving the paper towels on overnight for a total of about 12 hours had grout and caulk so crusted with mildew I thought it was beyond repair looking virtually as new.

Haven't seen your answer about your cleaning solutions on Travertine or marble. What 'cha think?

Once removed, would an application of bathroom type caulk that changed the profile help build-up in the future?

The bleach/paper towels worked beautifully! Now, after rinsing and wiping down the walls, do I need to reseal the grout?
Does the bleach weaken the grout?

Hi, Tim. Last year we started to get a leak between tub and tile. My husband applied silicone over the grout and now we are really getting a mess. I understand how to clean the grout, but what do I do with the silicone he applied? Thanks...great website!

I have an old yellow bathtub and cream tiles. I need to remove the caulking and need to know what to use on the mildew that will not discolor the tub.

A sweating tank is always caused by a slow leak in the flap. As fresh cold water flows in to top up the tank it becomes colder than the room and condenses water from the air.

Replace the flap, wiping down any grit where it seats, and the sweating will stop.

One product to keep mildew from returning is Tilex "Mildew Root".
Harder to find than the regular Tilex mildew cleaners, but works a lot better. I've found it at groceries and Target. Walmart type stores but only about one in four carry both types. http://www.tilex.com/mildew

We're having a new bathroom built at this minute. Is there something you can add to grout before it is applied that will prevent mold and mildew? Thanks. David

This was an EXCELLENT solution - thank you SO much!!!

I left the stuff on my walls and went out for a couple of hours with the window open, but on a rainy day to keep the humidity up/towels wet. I was amazaed how well this worked!! I never thought my tiles and grout would look this good again!!!

What about the effects of all that harsh cleaner on a septic system?

I have a shower & tub insert over my original tile(bathfitters) will this discolor the insert?

I have read your comments on cleaning grout. Will This process affect the carrera marble tiles I Have?

Sandra

I read all over the place that mixing bleach with vinegar is poisonous. Don't do it!

I'm going to try this but it might be too late for me. I had stains so bad that I removed the grout and re-grouted with a silicone grout that was supposed to resist mildew. I still have black stains on the new grout as well as on the tiles. The corners are especially bad. Hope this works, if you have further tips please post. I don't know why the mildew is so bad in there.

Thanks Tim! I followed your instructions precisely. My only recommendation is that you REALLY stress that the vinegar must be washed away completely. I guess I wasn't as thorough, and after letting the bleach sit for 3+ hours I ended up with really potent fumes!

Maybe I can update the remediation info given in this thread regarding chlorine bleach.

Chlorine will work fine on non-porous surfaces like glazed tile, but not so well on porous materials like cementitious grout.

Sodium hypochlorite, the active ingredient in liquid chlorine bleach, is ionic in nature. It will NOT penetrate into grout. However, the carrier in liquid bleach, water, will.

So liquid bleach is only a topical treatment and will kill any active mold/mildew on the surface, but the inert water will penetrate deep into the grout and, ironically, actually feed the mold!

Look into a mold remediation product like Shockwave that has ammonium chloride as its active ingredient. It sanitizes non-porous as well as porous materials.

No, I'm not affiliated with the product. I'm just trying to help out by providing better information.

Tim, this is genius, thank you so much! I stuck the paper towel to the tiles with a bit of water and then used a spray bottle of bleach to saturate them. That let me avoid most of the fumes. I didn't expect it would do much, because the mildew seemed to be under the grout, but it worked like magic!

It didn't whiten graying grout though... this stuff appears to have been added after construction and is a different color from the rest of the stall. Have you any suggestions?

I clean my shower every two weeks to take care of <a href="http://www.southjerseymoldtesting.com">mold removal</a>, and I'm fine. I will try to integrate some of your tips into my cleaning!

My husband and I did this this weekend and our showers looks like they are brand new!!!!! We started with the soft scrub, rinsed, then used the vinegar/paper towels and instead of chlorine bleach/paper towels we used old toothbrushes to get in between the grout. We were seriously considering buying a shower insert and now we won't have to!

Dear Tim,

I have a similar question to wg2ssg. I am considering buying a house that has natural, tumbled marble in the shower, and the grout at the joint between the wall and the floor has mildew. Will bleach or vinegar harm this type of tyle?

I am also wondering if the mildew could be deep, so that I may need to remove the grout?

This worked! I didn't believe it would at first - since I tried so many things to get rid of the disgusting mildew in our master bath - but I am thrilled to be proven wrong. The fumes were tough to handle, especially with toddlers in the home, but we closed our bedroom door & let the vinegar & bleach do their thing. Viola - a sparkling clean & white tile shower again! Thank you for sharing this tip!

I have colored grout and caulk in my shower with great ventilation. How do I clean the colored caulk that is in the bottom of my shower? The caulk everywhere else seems to be fine accept for there.

Well, OK, but so much for a "quick fix" idea. Regarding the hard water stains, boy those are really tough. That calcium must be some of the hardest, stickiest, toughest stuff on earth. I like your solution because I've never heard of attacking the problem with 8 hours of chemical warfare, but the idea of lining most of the shower with paper towels and keeping it supplied with vinegar strikes me as comical, but I like it. I've found that all those off the shelf products that feature photos of gleaming tile on the bottle do not work. The only success I've ever had is to scrape the calcium with a flat razor blade followed by heavy scrubbing and repeat until gleam, then follow with wax like "Jubilee Kitchen Wax" or "Meguair's Gold Class" car wax. That gets the gleam but takes about 4 hours of hard work to do a single shower.

Thanks!! Mildew has been building up in my shower for ~ 1 year. I finally decided to deal with it, and am very thankful I found this page.
I first tried commercial clearners. They were great for removing surface material, but did nothing on the mildew that was embedded in the grout.
I then tried scrubbing with diluted, (chlorine-based) bleach; this was promising, but was going to require several hours that I didn't have. It was apparent this solution did not hold a lot of promise.
I then found this solution. The job is currently in progress, but is already working wonderfully. Yes, there are fumes, but nothing too bad. If it is too much for you to stand, I would suggest doing this in stages. i.e., clean the corners of the shower first, then one wall, then another, ... You could also leave the exhaust fan on. Be sure to rinse the bleach well, and cover any metal parts (e.g., your drain). Bleach does corrode metal after prolonged, sustained exposure.
Yes, my shower was not pleasant, but thanks to this tip, it will soon be spot-free!

Hi Antresia,

My daughter is living where there is so much mold and midew in the bathroom shower, that I fear it is what is making everyone sick. Can you please help me.

Well, my shower was looking a bit moldy, especially on the corner caulk. I was ashamed :) and didn't know what to do. Tried various supermarket cleaners and nada except less money in my wallet.

Half heartedly I tried spraying 100% bleach as suggested (yeah, this is gonna work, right!) Well, I walked away for an hour or so and my eyes nearly popped out of my head. It was like brand new caulk, nearly all the spots were gone and it was brilliant white. This was only the first application and I was blown away. Great suggestion!

Now the caveats - bleach stinks so close the door, run the fan, and open some windows. It stinks, but its better than me standing in the shower scrubbing like a fool directly breathing in some other products fumes.

My tile is white and the grout is white so the only concern I had was with the silicon and rubber shower door parts. Haven't noticed a problem.

Many many hours of scrubbing save and many thanks to Tim!

We have Pink Mold growing in the flooring behind the bathroom.
This is not rsponding to Bleach or any cleaners put on top of the flooring. We are having trouble with breathing problems with our children. We resently moved to TX.last year the luxury apartment complex had a water barke in the walls on the effected bathoom. Pink mold grows very quickly on the shower curtain every 2 weeks. We are concerned for our saftey and want to get rid of the mold. Please advise what to do. Mataintance here has poured bleach on the area with no change and used a mold and mildew cleaner. no effect. They also have stated there is no such thing as PINK mold. Please advise what to do next.

Tried this method but didn't think to try a test spot for the vinegar step. The vinegar eroded all my grout :( So save yourself some trouble and try a test patch first. Don't learn the hard way like I did.

Please never use bleach and vinegar together. This produces a toxic gas.

Just wanted to let you know I had great results using bleach and baking soda instead of paper towels. It washed right off the next day and the mold was gone.

Instead of the paper towels I used baking soda mixed with the bleach. The results were excellent, no waste of paper towels and it washes right off with the shower head.

I had very old mildew stains in our shower stall that I was unable to remove with Tilex Mold & Mildew remover. I scrubbed the grout with Comet and tried the paper towel method and it made a big difference. Then I realized that i had an old Clorox Bleach Pen Gel and used it on the remaining stains. Guess what, they have disappeared after applying the gel a couple of times directly on the stains! Would highly recommend using the gel after scrubbin the stains. BTW - the gel does not emit the strong odor as straight bleach does.

This worked on my 70's shower and my grout looks pristine now!! cannot wait for my parents or boyfriend's parents to come down now and use the shower! I have recommended the paper towel technique to many friends and received no complaints that it did not work for them. Thank you!