How to remove vinegar stains on marble mosaic shower tile?

Q. I used vinegar to clean my mosaic shower tile, black and white pebbles of tumbled marble. I didn’t know I shouldn’t use vinegar. Now they are discolored. Do I just need to re-seal it?

A. We understand your concern about the discoloration on your shower tile after using vinegar for cleaning. First off, don't be too hard on yourself for making this mistake. It’s totally understandable! There’s so much advice floating around online telling people that vinegar is a great all-purpose cleaner, and unfortunately, that’s just not true for natural stone surfaces like yours.

The core issue here is the chemical reaction between the vinegar, which is acidic, and the calcium carbonate content in the tile, a common component in marble and similar natural stones. Vinegar’s acid reacts with this calcium carbonate, causing what is called etch damage. This etching actually dissolves thin layers of the stone’s surface, leading to a dull, rough, or discolored appearance.

It’s important to distinguish etch damage from simple staining. Stains are usually caused by dirt, oils, or dyes that sit on or soak into the surface, and those can often be cleaned or treated with the right products. Etch marks, on the other hand, are physical damage to the surface itself — the stone’s finish has been chemically altered or worn away.

In some cases where the stone surface is smooth and polished, a professional restoration specialist can use honing and polishing techniques to remove the damaged layer and restore the stone’s original appearance. However, because your tile is textured, this process becomes much more complicated. Polishing a textured surface evenly is difficult without affecting the texture itself, and many professionals may find it challenging to restore the finish perfectly.

Additionally, sealing the stone will not fix etch damage. Sealers protect the stone from future stains and spills, but they cannot repair or reverse chemical damage that has already occurred. Applying sealer over etched or discolored stone may even make the damage more noticeable because sealers can darken the stone’s surface.

Given these complexities, this is definitely not a do-it-yourself project. The best course of action is to consult with a qualified stone restoration professional who can assess the extent of the etching in person and recommend possible repair options. To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO.

In the meantime, to avoid further damage, we recommend stopping the use of acidic cleaners on your natural stone surfaces. Instead, use pH-neutral cleaners specifically designed for natural stone. 

Hopefully this information helps clarify the situation and guides you toward the best next steps.

ABOUT THE AUTHOR Fred Hueston is the Chief Technical Director at SurfaceCarePROS.com and Director at StoneForensics.com. He is also the author of Stone and Tile Restoration: The Manual, a comprehensive online manual for stone and tile restoration contractors. [Learn more about Fred.]