Here is what it looked like after treating the plywood with mold cleaner.
Behind the toilet
and by the tub
The cleaner did a pretty good job of removing the mold. There is still some black in the crevices where the wall and tub meets the floor. I am concerned about the swelling in the floor.
should I sink some stainless steel screws near the swollen seam first and the then sand it down flush?
Also, there are alot of holes in the plywood from where the carpet tack strip was nailed down. Should these be filled with some thing? There are rusted nails as well. Should I pull the rusted nails and replace with some SSteel screws?
My plan is to get the subfloor as clean and smooth as possible and then apply some Kills mildew resistant primer. Then mortar and screw down Wonderboard and then lay ceamic tile.
This bathroom does not have a window that opens but does have an exhaust fan. My two kids will be using this bathroom so it will be used frequently. I think I will wire the fan to always turn on when the light is switched on. I am also going to apply a new coat of paint with a anti-microbal additive. I will be relpacing the rod and curtain with a sliding door to help keep the water in the tub/shower enclosure where it belongs. I am also contemplating putting in a dehumidifier as well. Any advice on keeping this mold from returning is greatly appreciated.
Do you think I need to pull the subfloor and inspect underneath? I'm pretty sure that the moisture from the area by the tub was from people dripping as they exited the shower and the shower curtain being compromised.
Thanks again to everyone