How to Remove Mold & Mildew From Fiberglass

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Things You'll Need

  • Soft-bristled brush

  • Household bleach

  • Plastic bucket

  • Sponge

  • Fiberglass cleaner

  • Baking soda

  • Dehumidifier (optional)


Run a dehumidifier or increase ventilation in the affected room. Moisture and humidity are among the most common reasons for mold and mildew growth.


Avoid using abrasive cleaning products. These may scratch the fiberglass, making it easier for debris to collect and increasing the risk of future mold and mildew growth.

Mold and mildew spores are found everywhere, and will become visible mold growth if given the right conditions. Although mold doesn't grow or feed directly upon fiberglass, it often appears on debris and grime that's built-up on the fiberglass. Common problem areas include bathrooms, where fiberglass tubs can quickly become covered in mold. Mold not only stains, but may also pose a respiratory health hazard. Clean and remove mold and mildew on fiberglass to restore the fiberglass' appearance and protect your family's health.


Step 1

Splash water onto the mold and mildew growth. Brush the area with a soft-bristled brush to loosen surface debris and mold growth. Dampening the area helps minimize mold dust during the brushing process.

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Step 2

Kill the mold and mildew. Mix 1 quart of household bleach with 4 quarts of warm water in a plastic bucket. Pour the mixture onto the mold and mildew, thoroughly coating the fiberglass.


Step 3

Allow the solution to sit on the mold for 15 minutes, effectively sterilizing the area. Rinse away with fresh water to remove the bleach.

Step 4

Apply a household cleaning product intended for use on fiberglass. These products may be paste or liquid. Apply according to the manufacturer's instructions, as application techniques and potency vary by product. Alternatively, dust the fiberglass with a thin layer of baking soda.


Step 5

Scrub with a soft sponge, thoroughly scrubbing all exposed surfaces to remove soap, dirt, grime and body oils that may have built up on the fiberglass surface and are attracting mold. Rinse after cleaning.