Mystery #14: Where Did These Big Wood Floor Spots Come From? Part 2: The Answer!

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Last time I presented a new spot mystery. The two photos should have been all you needed to get the ball rolling.

Here’s how it all went down:

I received an email response to an old black spots blog post, and a homeowner sent me photos of some spots on her strip oak floor. It seemed pretty cut and dry, so I asked her to call me.

The first question I asked her was if she could wipe or scratch the spots off easily. She said "no" and verified they were stained into the finish. 

Note that all the spots are perfectly round and fairly even. If you watch “Forensic Files” or any other such crime scene investigation shows, you know that spots like this could only have dripped, not spattered or sprayed.

Now I was thinking: What liquid drips and stains floors this color? Two things jumped to mind: ammonia and animal urine. They were too uniform for animal urine, so it was obviously mechanical. I asked her if there was a sliding glass door, appliances, a cabinet with cleaning supplies nearby? She said, "No, nothing like that."

1 24 23 Wood Floor Spots Room Scene 63cff4373edf3I then asked if I could get a wider angle photo, and that’s when I saw the wall and the adjoining rooms. The spots disappeared just past the edge of the wall. So, someone had to be dripping something. 

I asked if they had a cleaning person, and she said yes, someone comes in twice a week. I asked if there were spots anywhere else, and she said no. I asked if the little print on the wall of the colorful birds was under glass.

She paused, then told me they had recently hung the print and … the cleaning person sprays it with window cleaner.

I then asked her to go find that cleaner, as most glass cleaners are ammonia-based. I said, “While you are looking, check anywhere glass may have been cleaned.” Seconds later, she sighed loudly and said, “Oh … there are more here … and here…”

She found the cleaner. I Googled the Safety Data Sheet that details all the chemical components, and sure enough: ammonia. 

Case cracked.

First, I suggested that moving forward she uses a window cleaner that is not ammonia-based.

Next, I suggested she call a qualified wood floor finisher, and we could discuss a “recipe” to possibly repair the stained areas. If the stains are not too deep, potentially a light scraping, mild sanding and blending with the right finish, or one good abrade-and-coat over the entire floor should make the floors right as rain. 

So, it wasn’t metal this time, but once again the flooring world was seeing spots! FYI, other thoughts that occurred to me: hair dye, puppy pee, lemon-scented ammonia that some people still use as a floor cleaner, soil and water from a potted plant, mud … anything that could have simply dripped and was not cast about or swiped. This stuff was airborne and settled perfectly as it did its damage. Someone sprayed and walked away. 

Keep those cards, letters and emails coming, floor pros!

[Editor's note: See all of Stephen Diggins' floor mysteries, including plenty of mysterious wood floor spots, here.]

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