How to Acid Wash Fireplace Rocks

Published: Nov 3, 2009
Updated: Nov 20, 2021
1 minute read

Things You Will Need

  • Gloves
  • Safety glasses
  • Liquid detergent
  • Bucket
  • Scrub brush
  • Phosphoric acid masonry cleaner
  • Spray bottle
  • Rags
  • Sponge

Make your fireplace stones gleam like new with phosphoric acid masonry cleaner and water. Even with the worst buildup, this do-it-yourself cleaning is manageable in two hours or less by most homeowners.

  1. Mix one bucket of warm water with half a cup of liquid detergent. Use a scrub brush and vigorously scrub each stone. Use rags dampened with clear water to rinse.

  2. Mix the recommended amount of phosphoric acid masonry cleaner with water. Different brands may require a different mixture, so follow directions carefully. Use a gloved hand to scrub the stones with the mixture. Allow the acid cleaner 10 to 15 minutes to strip away the residue on the stones. Rinse with clear water using the rags.

  3. Mix a spray bottle with warm water and one fourth cup of baking soda. Liberally spray the mixture on the surface of the stones. Scrub with a sponge. Rinse with water and let the stones air dry.

Resources

Tips

Cover surrounding floors and walls with a plastic drop cloth to protect from the caustic cleaner.

Learn more about various fireplace stone at fireplaces-fireplaces.com.

Warnings

Wear safety glasses and gloves when working with phosphoric acid cleaner.

Keep the area well ventilated from fumes.

Claudia Henning

Claudia Henning began her writing career as a "Lake Sun Leader" columnist in 1989. Her experience includes radio and Web writing, where she specializes in construction and home improvement project methods. She has an Associate of Science…

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