Bathroom mold, explained
When Bathroom Mold Is More Than a Cleaning Problem
Bathroom calls split into two groups. Surface mold on grout and caulk lives on soap film and shower spray, and it scrubs off. 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. Once mold roots into the silicone itself, bleach only lightens the color for a few weeks, so the bead has to be cut out, the joint dried and cleaned, and fresh mildew-resistant silicone laid in. Overhead, the ceiling above the shower collects condensation when the fan is too small, gets shut off right away, or blows into the attic rather than through an exterior cap.
Older tub surrounds often hide paper-faced drywall behind the tile, and paper is mold food once water gets past the grout. That's why Bathroom Mold Removal in Elk Plain so often involves a plumber and a remediator working the same job.