My tenant said she smelled a musty smell in bedroom. Long story short. We removed a wall in the bedroom which is/ also the back side of a tile shower and fiund mold. This is a. Very okd house and the bath fan is vented to and in accessible attic space I’m not sure if there is a roof leak or just an accumulation of moisture in the bathroom.

How should I approach this? My tenant appeared to wish to stay in the house. These are brand new tenants only been in the house a couple months. I’ve owned the place for 16 years and never had this issue.

You did not mention if the mold is in the attic or just the back of the shower wall or how extensive it is.

At Home Depot they sell a product called Concorbium which is said to be a mold killer. Plain bleach is said to not work as well. If it's not too bad or extensive I'd try it first. Sprat it all over the mold and wipe it down good to get rid of most of the mold, then spray again. Probably should wear an M-95 mask and gloves (also sold at HD).Then make sure there are no leaks. The vent fan needs to be routed outside if it is not already. Don't let it dump moisture into the attic. Make sure there are no leaks from the shower/tub plumbing, the area around the shower pan or where the tub meets the wall (cracks let water in and that makes mold grow.)

When the mold is gone I'd get some mold resistant paint and cover the area with a couple coats. Everything - the back of the wall, the studs, any attic area that had mold on it as well. (Just being extra diligent.

If the mold is really bad, you might need to call a mold removal company (expensive).

Once all the mold is gone, put the wall back together.

Make sure the vent fan goes on when the light goes on in the bath as some tenants don't automatically turn it on when showering.

I concur with using Concrobium. It is a bit pricey. You can make your own as well, but it puts the tenant's minds more at ease when they know I bought a specialty item to take care of the situation.

Find the reason for the growth, remedy it and be thankful your tenants are so nice.

When you have the moisture issue handled maybe put a removeable panel on that wall for easy access to the shower controls from behind. That will also allow you to be sure the moisture issue is gone.

I dealt with this recently in a tiled shower but the problem was in the ceiling of the place below. We had difficulty finding the source of the moisture. After trying everything else we finally realized that the walls behind the tile itself had degraded over time and the water was penetrating the grout lines.

Long story short we removed all the walls and rebuilt the upstairs shower and replaced the downstairs ceiling while both places were occupied.

To answer all your questions: The attic is not accessible however my tenant cut a small hole in a ceiling and took a pic with his cell. There is no mold in the attic and it looks to be in great condition. This is an old cape cod house and teh bath is on the second floor. I am thinking a prior guy I did business with perhaps did not use the correct board behind the tile?

What do you all suggest? I read about Go Board or Schlueter?

i think moisture is collecting behidn the tile wall due to any showers happening with the new tenants taht before I only had two and I now have6. Certaintly not saying that is it but maybe?

The proper way to install tile is over cement board. Many people shortcut by installing it over drywall, but even the mold resistant kind (green at HD, purple at Menards) is not waterproof and will eventually mold.

You've done the right thing: removed the compromised part and identified the source of the moisture. Rather than do a patch job on the one tiled wall, I'd pull it all down and put up a fiberglass surround. That makes it a cheaper, one-day project rather than one that goes on for several days.

Ideally, cement board that is properly sealed at the seams, covered with a Schluter Ditra membrane also all properly taped & sealed.

What class of rental and how much $ do you have / want to spend? How long do you want it to last?

I typically just use drywall as a backer for my tile. I have not had any problems yet with that, although I have removed a lot of rotted drywall from old tile jobs.

Cement board is the better way to go. Seal the edges up and have at it.

Rita.

Wet wood takes up to 14 days to dry with FAST MOVING AIR.

Bleach does not kill mold or mildew, just turns it white.

Before you close up the wall take several photos as evidence you cleaned up the site. You might need that when selling the home someday.

If your insurance hears about the "mold" your home will be "labeled" and the future buyer will not be able to get insurance without proof of proper remediation.