Friday, May 24, 2024

Sealing the Shower Floor

 We really like the newly remodeled master bathroom. Especially the shower.


However, after about a month of use, Linda noticed small black spots on the shower floor.



We think this is mold.

So two questions: (1) How to get rid of it? and (2) How to prevent it?

To get rid of it, I would normally spray it with a mold/mildew remover, which is basically bleach, but the internet says not to do that because (a) the tile is marble, (b) Marble is calium carbonate -- a form of limestone, (c) limestone is base and bleach is acidic, (d) bleach will eat away at the marble.  Instead I found a recipe for a cleaner for marble composed of:

  • 1.5 cups of water
  • 1 teaspoon dish soap
  • 3 tablespoons Rubbing Alcohol

I mixed that up in a spray bottle, then sprayed it on the tile and scrubbed it with a scrub brush. 

Once that was dry, we decided to seal the stone, to try to keep the mold out of it.  Marble is porous.  We decided to use BulletProof Sealer by StoneTech.

The hope is that this will seal the stone, and not allow the mold to get into it.

In addition, we are looking into using a UVC light to kill any mold.  A UVC light  (254 nm) is supposed to break down any DNA molecules and so kill the mold.  It is also damaging to people, so we will need to be careful.