I have always lived with real wood floors, often 100+ years old. We installed red oak floors last year and had someone finish them. He used Bona Traffic, which we used in a kitchen in our last house.

In the last few months, we've seen dark grey stains appear. Sometimes they are drip-like (a circle), sometimes an odd splash pattern, sometimes the pattern of the rug grip (but that same rug grip in another room has no problems). Behind the dryer it looks like small mold spots. The walls are fine, as is all the wood furniture, etc. Also, certain boards show the grey parts, and then the stain suddenly stops when there is a new board.

There has been no leaking of water or anything, and if someone spills water, we wipe it up immediately (except the kitchen, where it happens all the time, and there are no stains. We had a water filter where the spigot was right over the floor, and while the wood table it was on got a little water damage at the base of its leg, the floor under the leg and around it is just fine.

We don't use caustic products. I clean the floors with a broom, vacuum, and water (which is thoroughly dried). We don't use typical American products on ourselves or for laundry, etc., nor are we using something such as vinegar or alcohol that is natural but could cause problems. My parents use all the detergents and chemicals out there, and their floors are always fine.

My kitchen is just fine, despite it being a working kitchen for 6 people on a small farm (e.g., this week has endured pickle making, tomato sauce, peach jam, and feeding a teenager). My living room floor has been peed on during potty training incidents, and is fine.

Some of the floors are over crawlspace, some basement...there is no pattern to where the damage is.

The damaged parts are in rooms with water sources...and yet the wettest room, the kitchen, is fine. The bathroom does not have a shower, just a bathtub, and there are no interior doors (this is a many-year restoration project!), and the damage is actually near the door, on the farthest edge from the tub.

I'm a little suspicious that perhaps he didn't use enough product. The floors also feel rough/unclean--like perhaps the finish raised the grain.

I have been crazy about no one doing anything to these floors, which is not a sustainable way to live, nor how we have in all our other wood-floored houses. I am so sad that our huge effort to afford and install these floors looks terrible after 12 months.

Is there anything else that would help you answer these questions? Does anyone have experience with this happening, or have any ideas of what is going on? I will contact Bona with photos and descriptions of the situation. I don't see the floor finisher being very open to redoing/reimbursing if this was his fault.

Some other f the single component wood finishes are not as chemical resistant as the two component finish, so they are susceptible to stains? Was a hardener mixed in?

Water-based finish is applied in thinner coats so it takes more coats to protect the wood surface. How many coats were applied?

All I know is what was on the invoice: "One coat of Amber Seal and two coats of Traffic Satin Poly". I was hoping for oil-based (I don't mind the yellowing, and I even paint trim, doors, etc. with oil-based paint) but was steered toward this product. We used it in one room in our old house--we moved a year later--but it seemed fine. Not the prettiest finish, sort of homogenous and plastic-ish, but durable.

There's so much weird stuff--very straight lines, spots, splotches, circles...mostly grey, but some small white spots too. No problems with the walls (drywall), windows (new, and 100% wood), or furniture (all wood). I have wood furniture in my kitchen with just a thin and old coat of some tung oil that isn't looking like this, despite constant battering by my children doing things like canning pickles! If this wood was so fragile, or the finish so incredibly unstable, I can't imagine they would be used in millions of buildings. This is very disheartening to see this happen AND have to take such extreme care with these floors with the hopes that the damage will stop. I can't do this forever!

Bona suggested I talk to the floor contractor first. I was hoping they'd seen this before and could suggest what went wrong. So I'll do that now...

Its from the sealer application. The uneven application of the sealer is your issue. Amberseal and all pigmented sealers work better with two coats. The grey spots are where he put it on too thin or missed them all together.