Well, it’s been awhile since I could jump in here, talk shop and share old floor stories with our WFB readership, our “brothers-in-arms.” In this past year, unfortunately, I have had the misfortune of attending several funerals and family matters while trying to keep pace with the world simultaneously. I have been a speaker, pallbearer or presenter of “offerings” at all of them. Needless to say, the days and hours stacked up on me, and I needed some time to step back, take a break and collect myself. Thanks to so many caring people, especially my family and my employer, I was given that much-needed time and now have regained my focus in many valuable ways. I missed my time away from my coworkers, wood floor colleagues and customers, and while I was away, my mind was drawn back to many interesting (if not puzzling) hardwood floor experiences … and even floor nightmares (in my job, that’s an occupational hazard!). I would like to share them with you (or “y ’all,” to be fair to my friends down South). Moving on…

I want to throw out to you, our valuable and persistent readers, three situations that I will be looking into. Then I will explain the processes I will use to find a resolution to each issue. And, finally, I hope to share our results. All the issues I am dealing with are complete anomalies. These are strange-but-true stories of flooring gone wrong in inexplicable ways. We will follow the process together; you may share your insight and experiences (and potential hypotheses), and I will blog updates as events unravel. Let’s go!

Today I’m sharing Case Study #1: The Spreading Black Spots. Here’s the situation:

A man in a home built more than 70 years ago had his 2 ¼-inch red oak hardwood flooring that was original to the home sanded and finished. Very rapidly, what appeared to be black mold or mildew spread from the floor seams (gaps) and across the surface of the wood floor. I considered black iron oxide contamination, but such spots encapsulate once the finish is dry and do not spread. (For more on black spots, see my previous article “What Causes Mysterious Black Spots in Wood Floors”). Over several weeks and even months, the mysterious crud spread onto adjoining floors and materials: ceramic tile, sheet vinyl and then a leather sofa!

I am working with two laboratories on this bizarre floor problem. I think I know what this is … I need proof. What are your thoughts? Here are photos of the spots:

Post your thoughts in the comments, and I’ll update you on what I find out with this.

See more wood floor mysteries from Stephen Diggins:

Wood Floor Mystery #2: The Poly That Wouldn't Stick

Wood Floor Mystery #3: The Tale of the Half-Cupped Floors, Part 1

Wood Floor Mystery #4: How Did This Floor Get Like This?

Wood Floor Mystery #5: The Uniform Gaps

Wood Floor Mystery #6: The Case of the Crawling Finish

Wood Floor Mystery #7: The Case of the ‘Burned’ Floor

Wood Floor Mystery #8: Is This Floor Fungus Among Us?

Wood Floor Mystery #9: A 'Sight' Inspection of a 'Disappearing' Gunstock Wood Floor, Part 1


Stephen Diggins works for Wood Pro Inc. in their Derry, N.H., branch as manager and training director. He has many years of installation, sanding, finishing, gymnasium design and technical consulting experience, which he uses to assist his flooring customers on a regular basis. With 34 years in the flooring industry, he has been a freelance columnist for magazine, newsprint and online medias and has conducted product seminars ranging from wood flooring to luxury vinyl tile.