View Single Post
Unread 11-12-2021, 06:12 PM   #15
Veteran DIYer- Schluterville Graduate

STAR Senior Contributor

Join Date: Jul 2004
Location: Nashua, NH
Posts: 14,966
A couple of things you might guarantees!

IN addition to what's already been suggested, you might try Moldex solution. I tend to order it from Home Depot, as they seem to have the best price on a concentrated gallon, which lasts me usually at least a couple of years. I use it to clean the walls in my shower, and let it soak in the air tub's passages to manage the mold that likes to grow in the dark, moist passages.

There's a mix your own solution whose recipe I read here years ago that some swear by. A search should find it, but if I remember, it contains the following, but don't remember the concentrations:
- hydrogen peroxide
- methanol alcohol
- borax
- water

Again, this is from memory, so may be off a little: the H2O2 acts like a bleach, the alcohol works as a solvent, the borax shreds the cellular walls of the mold spores, and the water helps it all to flush it away.

Natural stone in a shower can be risky for the reasons you're seeing. A much less porous ceramic look-alike is often the better choice.
Jim DeBruycker
Not a pro, multiple Schluter Workshops (Schluterville and 2013 and 2014 at Schluter Headquarters), Mapei Training 2014, Laticrete Workshop 2014, Custom Building Products Workshop 2015, and Longtime Forum Participant.
jadnashua is offline   Reply With Quote