Removing Water Marks From Slate

Slate is prized as a natural flooring and counter top material thanks to its varying textures and hues. However, because it is unprocessed stone, slate is vulnerable to water marks like hard water rings and efflorescence. These marks are usually caused by spills, or by cleaning the slate with water or cleaning products but failing to wipe it dry. You'll find it fairly easy to remove water marks from slate, but the best method to use depends on the type of water mark you're dealing with.

Light Water Spots or Rings

1. Wipe the spot or ring with a damp cloth. Sometimes the spot is a minor accumulation of hard water that is easily wiped away.
2. Buff stubborn water spots and rings with fine steel wool or a nylon brush. Scour the spot gently until it is gone.
3. Wipe the surface of the slate with a damp cloth and dry thoroughly with a paper towel.

Efflorescence or Thick, Salty Spots

1. Dust mop or vacuum the spots if your slate surface is new, advises Bob Vila. You may have to do this until the slate dries out.
2. Dampen a cloth with vinegar and rub the spot, instructs Mintaro Slate.
3. Wipe the area with a damp cloth to remove vinegar and surface salts.
4. Mix 1/2 cup ammonia to a gallon of water for stubborn efflorescence or salty spots that vinegar does not remove.
5. Dip a sponge into the solution and wipe the spot clean. Limit your cleaning to the affected area.
6. Rinse the slate thoroughly with water and dry with a paper towel. Use ammonia only when other methods have failed. Frequent use of ammonia solution on natural stone such as slate can eventually dull the surface.

Things You Will Need

• Cloth
• Water
• Fine steel wool
• Paper towel
• Dust mop
• Vinegar
• Bucket
• Ammonia
• Sponge

Warning

Do not use water to remove powdery water spots. This will appear to solve the problem, but the salts will reappear when the slate has dried.

Do not use coarse steel wool or abrasive cleaning products. These may damage the finish of your slate tiles.

Avoid using limescale removers with an acid base. While these are ideal for removing hard water stains, they will leave etching marks on slate.

References

• Mintaro Slate: Laying and Cleaning Mintaro Slate
• Bob Vila: How to Clean Slate

Tips

• Prevent hard water marks on your slate by using distilled water to clean, or by adding a water softener to your water when cleaning.

Warnings

• Do not use water to remove powdery water spots. This will appear to solve the problem, but the salts will reappear when the slate has dried.
• Do not use coarse steel wool or abrasive cleaning products. These may damage the finish of your slate tiles.
• Avoid using limescale removers with an acid base. While these are ideal for removing hard water stains, they will leave etching marks on slate.