Can I safely use a steam mop on flagstone?

Q. I have interior darkly stained flagstone floors throughout the house and very difficult to clean with uneven surfaces. Can I use a steam mop on them without damage or lifting the color?

A. Steam mops can damage natural stone, including flagstone, as follows:

• Rapid heating causes stone, grout, fillers, and sealers to each expand and contract at different rates. This sudden temperature change creates internal stress, which can lead to damage, such as spalling, pitting or flaking.
• Steam can also break down or remove sealers. Color-enhancing sealers are often used on dark flagstone, and the color can lighten, dull, or become patchy when exposed to steam.
• If there are any existing cracks in your flagstone, steam can make them widen.
• Grout lines can discolor, crack, or lose its sealer.
• Stones that contain iron may oxidize when exposed to heat and moisture, causing rust stains that are very difficult to remove.
• If the stone contains fillers, steam can loosen or pop these out as well.

If your heart is set on using a steam mop, be sure to use only a lower-temperature residential steam mop. Even then, it should only be used very sparingly, no more than a few times per year. Regular or frequent steam cleaning is likely to cause cumulative damage.

Since you mentioned that your flagstone is darkly stained, using a steam mop could drive those contaminants deeper into pores and crevices. If this happens, discoloration may worsen.

For safe routine cleaning, use a pH-neutral stone cleaner, warm water, and a microfiber mop or soft brush. For more simple but important care instructions, download our free Stone and Tile Care Guide.

For deep cleaning, it is best to have a stone restoration professional handle the work to avoid damaging the stone or altering its color. To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO.

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: 838
Created: December 8, 2025
Last Updated: December 8, 2025
Author: Alice Dean

Online URL: https://surfacecarepros.com/kb/article/can-i-safely-use-a-steam-mop-on-flagstone-838.html