Yellowing marble is one of the most common problems owners of marble surfaces face. It can be frustrating to invest in marble for your home, only to see its elegant white color tainted. So why does marble yellow, and is there anything you can do about it when it does?
There are a few reasons why your marble surfaces might be yellowing. It could be the discoloration of a low-quality coating on the surface of the marble. It may be improper maintenance or insufficient maintenance, or rust within the marble’s substrate. I’ll summarize each of these in the best order for diagnosing the problem.
Yellowing marble because of improper or insufficient maintenance
Without regular and proper cleaning and care, dust and dirt may begin to collect in the pores of your marble. This is especially common on marble with a honed finish or on surfaces whose polish has faded. Given enough time, this pollution of the stone will cause it to tint yellow.
This problem is among the many reasons marble owners must diligently maintain their marble. For the average homeowner, a routine and thorough cleaning should be enough to prevent this from happening.
It is as easy as washing the whole surface of your marble counters with mild dish soap and a non-abrasive sponge. Don’t use the rough side of the sponge, and don’t use acidic cleaners! Acids will etch your marble, which can be an eyesore and tough to remedy. Abrasive sponges may scratch its surface. A complete, gentle cleaning once a week is sufficient.
Fixing the problem isn’t so difficult either. Use an alkaline marble cleaner (non-acidic!) and a soft brush to scrub the dirt from the pores. It may take multiple passes to get it all out, and it will likely leave your marble on the duller side. Depending on your goals, you may then want the surface to be polished or honed, but in whatever case, I highly encourage you to seal the marble with a high-quality penetrating sealer. If your marble is still yellow after a thorough scrubbing, you might face a different problem, such as…
Low-quality wax, sealer, or coatings
I frequently see marble surfaces treated with waxes (bad!), topical sealers, and other coatings that are either low-quality budget options or the wrong kind of coating for the stone – these surface coatings may yellow over time, which makes it seem like your marble has yellowed.
The good news is that this is a relatively easy problem to prevent and solve. As far as prevention goes, it is critical to only use penetrating sealers or other coatings on your marble surfaces explicitly designed for use on marble. Don’t use a topical sealer on marble! Furthermore, we never use wax on any natural stone, including floors, and we highly discourage doing so.
You want to seal your marble using a penetrating sealer with a robust warranty. If you want greater depth of color, consider an enhancing penetrating sealer. I do not recommend settling for the cheapest option you can find! Marble is a gorgeous stone that adds elegance to any space, and I encourage you to invest in coatings that will keep it at its best.
Where fixing a yellowed topical coating is concerned, you will likely need to strip it from the stone’s surface. Removing it requires using a stripper safe for marble and effective on the existing coating. You’ll likely also need to use an abrasive pad. However, if the pad is too rough or is misused, it could damage your marble. I highly recommend seeking professional help!
Once removed, don’t forget to apply a good penetrating sealer. For best results, I also recommend hiring a professional. It is possible to do this yourself, but the cost of a mistake could be higher than that of an expert and experienced pro! If stripping the marble doesn’t get rid of the yellow color, I have bad news…
Rust is a very challenging problem to solve. Marble is a very porous natural stone. That means when marble is unsealed or improperly sealed, water may seep into its pores, which may, in turn, react with iron that already exists within the marble and rust, creating that yellow color. Preventing rust is perhaps the most important reason to use a high-quality, penetrating sealer on your marble. If you are protecting your countertops, use TuffSkin Surface Protection, which prevents liquids from entering the substrate altogether!
If, however, it is too late, and you have deduced that the yellow color on your marble is probably because of rust, then you could try to apply a poultice composed of sodium hydrosulfite and sodium metabisulfite. These are the primary ingredients in a product called Iron OUT, which you can probably find at your local hardware store. We have also tried using Lime-a-Way.
Using these products may or may not work. In our experience, it is a coin flip. It is unlikely that you will be able to purge all of the rust from within your marble, which leaves replacing the stone as your only option. If you believe it is worth the time and cost to give it a shot with these solutions, try following these instructions from surpHaces.
Yellowing marble is an easily preventable problem with proper, consistent care. Depending on the reason, it is possible to restore your marble to perfect whiteness, but if rust is staining your marble from within the substrate, you may need to replace the marble entirely.
Take good care of your marble surfaces by routinely applying a high-quality penetrating sealer (or Tuffskin on counters). Clean your marble regularly with mild dish soap and a soft sponge. Follow these steps, and it is unlikely you will have any issues. If you have yellowed marble that you need fixed, and you are in Santa Barbara, give us a call, and we’d be happy to help!