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Best Way to Remove Mold and Mildew from Tile Grout

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Grout Mildew on Tile

As a bathtub re-finisher, I am constantly asked how to remove mold and mildew from around the tub and within the grout lines on the tile surround or inside a shower.  It is actually black mildew that we are fighting and it’s not an easy fight.

Mildew binds itself to porous areas and areas that give it a surface to cling to such as silicone caulk.  When you have mildew on the caulk between a bathtub and the surround it is best to remove it and just start over with a non-silicone caulk with a mildew resistant micro-ban additive.

Take a utility knife and score the old caulk length-wise from the top and from the side repeatedly until you have the majority removed.  Then take your window scraper razor blade and go after the rest.  Before you caulk it back in get all the nearby mildew (on the tile grout) removed as well.

Mildew thrives in a higher PH environment.  Soap and minerals have higher PH levels and thus encourage mildew to grow.  Staying on top of soap and minerals is the way to keep mildew at bay and this is done with a more acidic, lower PH cleaner such as Barkeepers Friend, which I highly recommend.


The key to removing mildew is by keeping a strong bleach solution on top of the affected area for a good amount of time.  Having a strong grout brush is also important to impregnate the solution into the grout and work the mildew loose.

Follow all the safety precautions found on the following product.  I haven’t been able to find this product in local stores but you might be able to in your area.

Here it is.  The highest rated grout cleaner I have found.  Just follow the directions on the bottle.  You might need more than one application but it beats the heck out of all the alternatives I have tried.

Home Armor Mold and Mildew Remover

Home Armor Instant Mold and Mildew Remover

“This stuff is awesome!
By rbflei “rbman” (Texas)
Whenever I use this stuff it melts mold. I have used this on stuff bleach didn’t touch. Seriously With mold problems just spray it on and watch mold disappear. If course It kind of makes me wonder what’s happening to my lungs as I spray it, but this stuff works. I had a problem w/ our toilet water making a black mold on the inside of the toilet that I spent hours scrubbing to no avail. I sprayed this on one day with a hope and a prayer and in about 2 seconds there was no mold. Used it in window corners that were left open to the elements and I didn’t even have to scrub it melted the mold away. We always keep a bottle now it is the ultimate around the house mold remover.”

Stay at it and you will get rid of that mold and mildew in your grout!

While we are on the subject of cleaning, do you have hard to remove stains on your bathtub?