Dear Maurizio, we had a few cracked 18 x 18" honed travertine tiles replaced in our family room floor about 3 years ago (by the original installer). We put a rug down over these tiles about a month after the repair. Some time later we removed the rug for cleaning and there was a moldy/mildewy smell emanating from these tiles, and a stain on the back of the rug. We cleaned the tiles and the rug and after a month put the rug back down. Thought the problem was resolved, however we just pulled the rug for cleaning again and the smell is worse than ever. Nothing we've tried gets rid of the smell. No pets in the house or plumbing pipes in the area. Floor is on a slab. Any clue on what could be causing it and what we can use to clean/deodorize the floor? Thanks
Dear Colleen:
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Any clue on what could be causing it"
Yes, I do know what caused the [moisture] staining: since the floor is set on a slab on grade, the activity of the water table under the house made so that some moisture wicked through the slab, the setting material and the floor tiles. Travertine is a top-notch stone for withstanding this activity that's called osmosis unscathed. As log it has the opportunity to "breathe" freely, that is. With a rug on top that acts like a "sealer" the moisture that comes to the surface of the stone gets trapped and creates a darker staining, which may be only water but may also include - as I suspect in this case - some agent (whether discoloring or not) coming from the rug that probably is also the cause of the odor.
What to do?
Depending on how large the rug is, it could be a project; therefore I recommend to have a bona-fide stone restoration contractor get into the picture. The best course of action would be let that section of the floor dry completely for a few weeks and then to poultice the entire affected area with Hydrogen Peroxyde 30/40 volume (clear). That should take care of both the staining agent (if any) and the odor.
After that, the stone pro will have to re-hone that area with a good-quality honing powder to blend in with the original finish as much as possible. Don't panic if the match will not be perfect: a few months of foot traffic will take care of finishing the job.
And no more rug, of course!!...
J