We are often asked what cause white marble to turn yellow over time. So we thought we would give the causes and cures, and why we recommend white or very light marble never be used in a shower.
Recently a home owner called asking about his white marble floor that has turned yellow. In this case, a water pipe had flooded the white marble floor area, and the home owner related the discoloration to the recent flooding. Although flooding is a common cause of yellowed white marble, there are several other reasons this color change will occur. Here are other common causes white marble to turn yellow.
Improper Maintenance
As your marble floor wears, the highly polished surface begins to become worn and even scratched. This wear and tear on your marble polish causes the surface to become rough, pitted and scratched making it a perfect magnet for dirt and debris. Since your marble flooring is porous, using improper cleaning products can cause the pores in your white marble to collect dirt and discolor to a yellow or even brown. Improper maintenance can include substandard cleaning products, using a dirty mop, and infrequent cleaning are the most common causes of yellowing of your white marble.
The Cure
Be sure the stone cleaner you buy needs to be alkaline and not an acid since acid cleaners will dull the polish. Apply the cleaner to the marble and scrub with a soft brush. Be sure to rinse the floor thoroughly. It may be necessary to repeat this procedure several times to remove all the imbedded dirt. If after cleaning the marble is dull I would suggest that you call us to professionally re-polish your floors then follow with an application of a quality penetrating sealer. If after several cleanings the yellowing is not removed then consider the next cause.
Wax Build-up or Coating
Marble flooring can be coated with waxes, acrylics, urethane and many other coatings. Most of these coatings are not designed specifically for the use on marble flooring. In addition to these coatings not being made for marble floors, the poor quality of these coatings can also cause your white marble floor to turn yellow. As these coatings are applied in multiple coats, it becomes soft allowing dirt and debris to become embedded in the soft layer of coatings or wax. These coatings require frequent stripping, which is often neglected.
Another possibility along these same lines is that process sometimes used for polishing marble floors is known as re-crystallazation. If this process is applied to a white marble floor that contains moisture it will turn the marble yellow.
The Cure
To remove yellowing due to a wax or coating buildup the marble will need to stripped with a commercial wax stripper. I would strongly suggest having this done by a professional. These strippers often require the use of abrasive pads which can scratch and damage the marble surface. If you do try it yourself, before undertaking the entire project perform a small test to determine results.
If the marble tile has been recrystallized, it will be necessary to remove the recrystallized layer. This layer can often be removed by a professional polishing the tile with a powder marble polish containing oxalic acid. If this technique fails then the tile will have to be re-honed. It is strongly suggested that the polishing and honing procedure be performed by trained individuals. If these techniques fail to remove the yellowing then proceed to the next possible cause.
Iron Staining
Your white marble flooring naturally contain iron deposits. As the iron becomes oxidized due to its exposure to water, acidic cleaners and household bleach, it will discolor your polished white marble stone.
It is for this reason that we recommend not using white marble in a shower.
A common cause for your white marble stone to turn brown is iron oxidation. This process can be accelerated as in the flooding example previously mentioned. Oxidation is similar to the rusting of metal as a result of the metal being exposed to air and water. If water and air is eliminated, the iron will not oxidize. This is the same reason white marble discolors to yellow or brown.
If left unattended, the process is difficult to reverse and replacement of the tile may be necessary.
Let Us Help With Your Marble Floor Restoration Needs
The yellowing of white marble is a common problem. New installations should be sealed with a good quality penetrating sealer (impregnator) which will help prevent oxidation of the iron by eliminating moisture. Bizaillion Floors, LLC. has over 35 years of marble floor restoration, cleaning and polishing. Restoring your marble floors to their original shine and beauty is our specialty. Whether it is yellowing from oxidation and lackluster maintenance, water staining, or abrasions and scratching, Bizaillion Floors, LLC. can help. Call us at 281-894-7823 or tell us how we can help with our contact form, and let us restore your marble floor to its original shine.