How can I clean mildew off of shower tiles without ruining the grout?
One of the biggest mistakes cleaning staff make when cleaning shower tiles and grout is using too caustic an acid or acid cleaner, which eventually eats away at the grout. The only acid recommended for this type of work is phosphoric acid. Hyrocloric and muriatic acid are too strong for surfaces and are dangerous for workers. A proper cleaning program for shower tiles should include frequent use of a neutral disinfectant to remove body oils and other soil. Then, depending on the area and its amount of traffic, periodic deep cleaning with a phosphoric acid-based cleaner will break down mineral deposits where mold and mildew tend to reside. But even daily use of phosphoric acids can wear down grout and tile surfaces, so it should be used as needed. Methods to apply acid cleaners include foam guns, which take more dwell time, sprays or the old-fashioned apply and scrub method. Mold and mildew need certain conditions to grow, including moisture, warmth and enough food (body oils and other
