Q. I installed Lasa White marble on my floor, and after about 15 days, yellow stains appeared across the entire surface. I used a stain remover, and the stains were removed, but they returned after two days. Please advise what I should do.
A. The fact that the stains reappear after being temporarily removed gives us important clues about what’s happening. Possible causes of the yellow stains include trapped moisture, iron oxidation (rust), or improper mortar or adhesives. Let's look at each.
Lasa White marble is very sensitive. Moisture from the subfloor, screed, or adhesive can migrate upward, carrying impurities. This can cause yellow discoloration that reappears after cleaning. In addition, if no waterproofing or vapor barrier was used, ongoing moisture movement may continue feeding yellow stains.
Iron oxidation, or rust, is caused when natural iron deposits within the marble or in the bedding materials oxidize with moisture exposure, creating yellow or rust-like stains that return repeatedly.
Cement-based adhesives with high moisture content or impurities can cause staining in white marbles, especially if the stone wasn’t fully dry at installation.
Improper cleaners fail to address the source of staining, so the discoloration resurfaces within days.
Regardless of the cause, this issue is almost certainly not a problem that can be resolved using DIY methods. The source of these yellow stains is likely below or within the stone.
A qualified stone restoration professional can perform a variety of tests to accurately diagnose the cause or causes of the discoloration. To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO.
Your PRO can:
What should you do in the meantime? First, stop using stain removers or cleaners on the marble. You could run into all kinds of problems. For example, rust removers may cause etching which will require professional honing and polishing. Clay-based poultice powders can drive rust stains further into the stone or even cause new rust staining. Bleach can make rust stains worse.
You should also avoid sealing the stone until the root cause of the yellow discoloration is identified, because sealing can trap stains permanently.
Acting early with the right expertise gives you the best chance of restoring and protecting your Lasa White marble floor.
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.]
Article ID: 867
Created: January 21, 2026
Last Updated: January 25, 2026
Author: Fred Hueston
Online URL: https://surfacecarepros.com/kb/article/why-do-yellow-stains-keep-returning-on-newly-installed-lasa-white-marble-flooring-867.html