Bleach treats the symptom. We remove the wet wall it grows on.
If your Cromwell tub surround grows black grout no cleaner defeats, the problem is behind the tile, not on it: water wicking through failed grout into drywall or greenboard that was never meant to get wet. Painting over it with 'mold paint' or re-caulking buys months. The fix is a half-day of honest demo — open the wet section, dry and treat the framing, rebuild on cement board and membrane — then tile that never feeds mold again.
Builder-grade tub-shower combos from the 80s and 90s dominate: one-piece surrounds, plastic trim, grout-free but ugly. Homeowners keep the tub footprint and gain everything by tiling the walls properly. Cromwell's 80s subdivisions are all hitting surround age at once — the same yellowed unit in fifty houses on one street. Bring us the smell and the stains; we will bring the meter and tell you the truth, including when the truth is 'just re-caulk it.'
Surround tile we set most in Cromwell — each suits different baths and budgets.
Surface mildew, yes — a deep clean and seal fixes it. But grout that regrows black within weeks signals water behind the tile, which cleaning can't reach. We meter-test to tell the difference free.
Most bathroom mold is allergenic rather than toxic, but it signals a wet wall cavity that rots framing and feeds worse growth. The wall matters more than the species — fix the leak path.
Only what's wet. Moisture readings map the damage; dry sections can stay. About half our mold calls need full rebuilds, half need section repair plus re-caulk and ventilation fixes.
Typically $200–$600 for contained treatment during a rebuild: demo of wet board, drying, treatment and documentation. Extensive framing damage is priced with photos first.