How to Remove Mildew Stains From Limestone

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Things You'll Need

  • Bucket

  • Bleach

  • Water

  • Scrub brush

  • Sponge

  • Hose


The Centers for Disease Control recommends using a strong bleach solution, containing 1 cup of bleach per 1 cup of water, when cleaning mildew left behind after a flood. After you clean, be sure to rinse the area well.

Clean mildew stains from limestone with a mild bleach solution.

Limestone is often used to accent patios, pools and bathrooms. These high-moisture areas leave limestone prone to developing mildew stains over time. Use of the wrong product could damage the stone. Never use acidic products that contain vinegar, ammonia or even citric acid to clean limestone. Instead, use a mild bleach solution, which will not react with the stone or its sealant. Once you have finished cleaning, be sure to rinse the area thoroughly.


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Step 1

Mix a solution of 1 tbsp. bleach and 1 gallon warm water, or 1 tsp. bleach in 1 qt. of water.

Step 2

Dip your scrub brush in the water, then use it to scrub the mildewed area.

Step 3

Leave the bleach to penetrate the limestone for five minutes.

Step 4

Scrub the area again.

Step 5

Wipe up the bleach cleaner with a clean sponge or rinse the bleach solution away with a hose.



Meg Butler

Based in Houston, Texas, Meg Butler is a professional farmer, house flipper and landscaper. When not busy learning about homes and appliances she's sharing that knowledge. Butler began blogging, editing and writing in 2000. Her work has appered in the "Houston Press" and several other publications. She has an A.A. in journalism and a B.A. in history from New York University.