Perhaps the Minwax stain was not sufficiently dry before applying the Bona finish. Or the finish has not totally cured. Or you live in a too tightly sealed dwelling. Bona waterbourne polyurethanes are usually totally cured in about 7 - 10 days.

What you're describing should be cause by the products used, especially after 3 months. Did you do anything else in the room? Repaint? Any new furniture? Drapes or blinds? An area rug?

You say this is in addition. How old is the addition?

jfcwood has some good areas to look for possible sources other than the refinish. This can be difficult to track down.

There was a leak in the wall, which is why we had to replace the hardwoods. We had the mold in the wall and floors remediated, new wood in walls, new drywall, new trim, all repainted. New hardwoods, stained and finished. It's definitely on or in the floor, because you can bend down to the floor and smell it directly on the surface. We have done air quality testing; there are no elevated levels of mold or anything else bad. We have replaced the rug that was in here and the curtains. We have moved all the furniture out of here; the furniture does not smell (and I washed the slipcovers in any event). The addition is 1991, FYI, but pretty much everything in this room is new, given the leak/remediation/repair we had.

This has definitely been difficult to track down! I have been working at it for about three months. We haven't used our family room since. It's been quite a mess.

What kind of "new wood in walls"? I looked at a job recently where the plywood in the walls was outgassing.
It makes no sense that the floor finish would smell, especially after months, but perhaps sanding off the old finish would eliminate it as a cause. Additionally you may want to remove the rug and drapes from the room temporarily to eliminate them also.

I already have removed the drapes and rug (and cleaned them; they no longer smell). The wood isn't it, because I smell it on the floor on the other side of the room, far from that corner where the leak was. They were 2x4s; the studs in the wall were moldy and wet from the leak.

was the subfloor replaced too?

Yes. Down to the slab. Slab cleaned and disinfected. Was open for almost a week to dry. Then joists, subfloor, and hardwoods replaced.

What was the Moisture reading on the subfloor before the hardwood was installed? any chance they used pressure treated subfloor?

They used pressure treated 2x4s that were on top of the slab foundation, but not pressure treated plywood as subfloor, I don't think. Why? No moisture under the floor, according to testing.

how sure are you that they managed to thoroughly clean the concrete? if everything was replaced, Bona wouldnt give off the odor your describing, especially at the 3 month mark. It sounds like from what you said, the concrete slab was the only thing that wasnt replaced.

Numerous people have had issues with getting pet urine out of concrete, as well as other stains/odors. its feasible that your slab wasnt cleaned as well as you think.

The mold remediation guy told me that he cleaned it thoroughly and it did not smell when the slab was exposed. Only once the wood floor was down and finished.

Well if you are satisfied with the cleaning that was done, and cant determine another source, then refinish the floor with a different finish and see if its any better.

Certainly the cheapest and easiest thing to do is to sand off the existing finish. I suggest you sand it off and leave it like that for a while. Once the finish is sanded off, there's no possibility it could be causing the smell.

I'm with gregmills in thinking that the smell isn't coming from the finish. The stain is formulated with highly volatile solvents that evaporate quickly so the water based finish can be applied within a few hours. Unless you're extraordinarily sensitive, there's no way you could describe the smell of the water based urethane as being offensive. It doesn't add up, but it's impossible to diagnose the problem remotely.

If the smell persists, look for the next likely culprit. If the smell goes away, look for another finish to substitute and finish the floor.

I agree with what you are saying about the finish not smelling, but I honestly don't know what else it could be. The slab was cleaned and dried out, and the smell is concentrated in the middle of the room, so it's not likely that water penetrated that far into the slab from the sides (from rain), and it's like 10 in. thick, so not likely from the ground, either. There isn't a water source that's leaking or anything - we checked that. I am stumped. It's not a strong smell; but enough that I can smell it, admitting, though, that I am very sensitive to smells.

Have you tried an air purifier?

I used to send my rugs to be cleaned by an ozinator which got rid of smells. I have heard ozone can be unsafe, so do your research.

I have an old ionic breeze from sharper image which has the same smell as ozone. I think it helps a little with the stain smells.

Yep. Tried it.

did you every figure out this mystery? Was it a wet rag in a wall cavity or a new draft created with the addition drawing in damp wet air from a crawl space?

Something else to consider, your wood subfloor and the pressure treated 2x4s have tons of chemicals in them, which could be seeping into your wood floor. A few years ago there were lawsuits over wood building products that had excessively high levels of formaldehyde. Enough so that people walked away from new homes because of the noxious smells.

I'm going to ask a really stupid question: was a vapour barrier used BETWEEN the slab and the new wooden joists (of the subfloor system)? If the slab is from 1991 it is *possible the vapour barrier is missing from underneath the slab OR it has been compromised in the 30 years since the slab was poured.

The fact the smell emanates from the CENTRE of the room doesn't bother me. Damp soil is damp soil is damp soil. A 'raw' concrete slab sitting on raw earth = damp slab.

Just for sh!ts and giggles, go ahead and ask your contractor if a vapour barrier was used underneath the subfloor system.

Did ANYONE test the concrete slab for moisture levels BEFORE it was covered up with the subfloor system? And the plywood over the joists was tested for MC as well?

Hello. Sorry to resuscitate this 5 years old post but I have the same problem as you. Hardwood floors were finished with Bona Protector and even after 1 year there is a finish/chemical smell coming from the floor on humid and hot days. I have also checked for mold and it came out negative.

Hi All

We just had the entire first floor of our house refinished with Bona clear and no stain. After a week or two it seems to smell like rancid vegetable oil. It may be more pronounced when the windows were opened and like Raed, it was pretty darn humid. I notice it when I come in from outside or from upstairs. After I am in the house for a while I can't smell it very much. But I have been having headaches.

Control your indoor humidity and it will stop. Use whole home humidity control and you will be fine. Change your HVAC filters every month for awhile = helps a lot.

The high humidity have been prolonging cure time. If, you have old floors with gaps in it. The cure time will be longer in the gaps. You can get a air scrubber to help filter out the smell or stick a portable dehumifier in the area to help pull out the humidity to force it to cure.

did you ever figure out what caused the smell?

Oh man… we are having this same problem… did you ever find the solution?!?

We had wood floors sanded and then 1 coat of Bona Intense seal and 2 coats Traffic HD applied. I saw the products. All 3 coats were done same day. Floor continues to smell 12 weeks later even though we aired out home with fans for weeks. Smell is less than at the beginning but still there and my wife feels light headed. Noticed when we get humidity to around 40% smell is less but starts again if humidity goes to 50-55%. Finish is rough but seems to resist water stains. How do we get smell to stop? I can put my nose on floor and know that is the smell.

Any insight would be very appreciated!

We are going on 18 weeks and it smells, especially in one room. Unfortunately I think you just have to wait. It’s better than it was… it has gotten better. I did read about this product that I was looking at using - but don’t feel like spending the $$ so just waiting it out - https://www.greenbuildingsupply.com/All-Products/Paints-Coatings-Wood-Stains-Sealers/AFM-SafeCoat-Polyureseal-BP

Thank you for your insight. What products did you have applied and over how many days? Ours is better than at the start but seems stuck at same level of smell. I looked at the AFM info you sent and saw that they say you can actually apply this on top of the current Bona coating to seal in the smell and not have to remove what we just paid for with the Bona. That may be an option we explore if this does not improve. I don't want to spend more $ and go through the pain of removing all the furniture and being out of the house but we may not have another option. Thanks again!

I hear you… we are just living with it and hoping it wears off…

I am trying to figure out what went wrong. What products did they use, how many coats, and did they apply all on same day?