Bathroom mold, explained
Surface Spots or Something Behind the Tile in Your Emma Bathroom?
Every bathroom mold call falls into one of two buckets. Some of it is surface growth on grout lines and caulk, feeding on body oils and soap scum, and a good cleaning handles it. The harder cases are growing out of sight, in the wall behind the tub surround or in the subfloor, kept damp by a cracked shower pan liner, a dripping valve body or a toilet seal that's been seeping for a long time.
People fight caulk mold for years without winning. When the growth is inside the bead, no spray will reach it; the old silicone gets sliced out with a razor, the gap is dried and treated, and new caulk goes in. Ceilings are the other hot spot: steam from long showers condenses on cold drywall above the tub when the exhaust fan is undersized, isn't run long enough, or vents into the attic instead of outdoors.
In a lot of older baths, the tile was set over standard paper-faced drywall instead of cement board, and that facing feeds mold as soon as moisture reaches it. That's why Bathroom Mold Removal in Emma so often involves a plumber and a remediator working the same job.