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Mildew on grout in shower

Posted by cista (My Page) on
Sat, Nov 17, 07 at 15:52

I've had a horrible problem with mildew on the grout in my shower for the past few months. I can clean it and the mildew is back in a day or so. We've been in this house (new) for less than two years and it didn't start happening until a few months ago. Any ideas about why it would be happening now? How often does grout need to be sealed? Could that be the problem?



Follow-Up Postings:

RE: Mildew on grout in shower

I don't know if this makes any difference, but did you ever apply a sealer to the grout? Builders and remodelers do not seal the grout - they leave it up to you to do.

But even if it isn't sealed, you shouldn't be getting mildew if the shower stall is properly ventilated.

If it were my house, I would do several things: a water test on the grout to see if it needs to be sealed or resealed; a really good cleaning with a bleach solution, and then figure out how to ventilate the area better.

In one house that we lived in, we bought a tower fan that had a built-in timer. We placed it in front of the shower stall and set it to run for an hour after everyone had showered.

RE: Mildew on grout in shower

I've got mine sprayed with bleach right now. Getting mold on a few grout lines where tile meets tub. Its been gone for a long time, since I realized I should leave the shower doors open on both sides till shower dries. I always have the window open in summer, but now that its cold, there is less air movement in there so it takes even longer to dry I'm thinking.

Do you run an exhaust fan when you shower? That helps too and you're supposed to leave it running for at least 20 minutes afterwards to get moisture out of the room. I don't leave it running that long, but know I should.

Graywings, good idea about the fan, but it would be in the way here. Sandy

RE: Mildew on grout in shower

"Getting mold on a few grout lines where tile meets tub" that area should be chaulked w/siliconized latex chalk - not grout

RE: Mildew on grout in shower

The guy that installed the tile sealed all of the grout in the house. That was a little over a year and a half ago. I'm going to get more sealant this wknd and do it over, just in case. I really hope that will cure my problem. I cleaned it quite well and now 1) run the exhaust fan 2) spray the shower with "No Work" after each shower and 3) prop the shower door open. The shower has 1.5 glass walls and 2.5 tile walls. I can see where it isn't getting a whole lot of ventilation even though the top is open.

Thanks so much for your replies.

RE: Mildew on grout in shower


Don't put more sealant on the grout until you are SURE the mildew is gone. If the mildew is behind, or in the grout, and you seal it, you'll never get the grout clean.

It sounds like you may have a problem with the ventilation. Make sure the fan runs about an hour after everyone is done in the bathroom.


RE: Mildew on grout in shower

I too am having the same problem.

I have been using the Clorox Bleach Pen. I draw a line on the grout and let it sit for an hour. Then I take a toothbrush and scrub it off, then rinse.

This does us for a month or so and then the black is back on the grout. We do run the ceiling vent and open the window.

I am thinking that we need a stronger powered ceiling vent installed.

RE: Mildew on grout in shower

I bought some mildew remover in the bathroom cleaner section of the store - no idea what brand, I expect they all work.

When mold shows up I spray it with the mildew remover and it stays gone about a week.

We have trouble in the spring and the fall here with mold in the bathrooms.

RE: Mildew on grout in shower

We had similar problem. Mold was trapped in by lime and or soap scum. We had to get rid of that first. KABOOM! I also use boat hull cleaner to white grout. It is a form of O2. Water soluable.

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