How to get rid of severe black mold on bathroom grout
Normal household cleaning products often fail to clear deep black mold on old bathroom grout, leaving tenants to figure out if they need to regrout or get the landlord to intervene. Left untreated, severe mold leads people to worry about structural damage and forces them to use dehumidifiers just to slow it down while trying to decide what needs to be replaced.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Using normal cleaning products provided by the landlord
- 2Using industrial strength peroxide or specialized mold and mildew removers like RMR-86
- 3Running a dehumidifier 24/7
- 4Destroying and replacing the affected drywall
- 5Adding ventilation or checking for hidden water leaks
- 6Using a pinpoint steam wand
- 7Scrubbing with an old toothbrush
- 8Making a paste out of dish soap, peroxide, baking soda, and water with a grout brush
- 9Using specialized commercial grout cleaners
- 10Using a dehumidifier to improve room humidity levels
- 11Spraying moldicide products like Concorbium
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“I'm moving out and trying to clean before inspection and I can't get this black stuff out.”source ↗
“We have a small bathroom with no window and poor ventilation, which has caused quite a lot of mold on the walls, ceiling, and grout.”source ↗
“Is this something we can DIY? What’s the correct order of steps, and what products would you recommend, especially ones available in Israel?”source ↗
“Also, should we clean the grout or replace it?”source ↗
“The mold on the bathroom grout is plenty and completely black.”source ↗
“I don’t think normal cleaning products will work but my landlord said that is what he purchased to fixed more than a week ago with no fix.”source ↗
“Should I try to regrout it? Is that a thing?”source ↗
“Yikes, I really hope it doesn't come to breaking down the wall! 🙈 I'll definitely inspect everything I can first, thanks for the heads up!”source ↗
“Oh no, that sounds like a total nightmare 😭 I'm looking into getting a dehumidifier today to slow it down while I figure out what to replace. Thanks for the honest advice! 🙏”source ↗
“Everyone says peroxide, but I'm honestly at the point where I'm scraping up grout scrubbing so much. Hopefully you find a way. I fear I'll have to regrout which seems like a daunting, labor intensive task”source ↗
Where this came up
People with this problem also raised
- 5How to clean mold on drywall or know when to cut it out
- 6How to fix white spots on a shower floor finish
- 6How to clean mold under water damaged flooring without DIY experience
- 2Why does a white crust keep coming back on my bathroom sink?
- 4How to clean a really mouldy rental shower and fix the caulk
- 5Should I put caulk over missing grout in shower corners?