Poly Flaking Off and White Between Boards

Q: We have an 18 yr old white oak floor that was recently refinished. There were some errors in the staining in a few areas and these were redone. Now some of the poly is flaking off in the cracks and also on the boards themselves. This are also noticeable cracks, where it is turning white between boards.

What is the best fix for this? What is the cause? They were done by a reputable company.

A: I would need to know what finishes they used. White oak is one of my favorite woods but it can have issues at time due to high tannin content. Finish turning white isn’t one of them.

Follow-up Q: They used oil based stain and oil based poly. Would high humidity and not enough drying time be a cause? They are returning next week to redo everything (with a much more experienced team) and we want to make sure it turns out right. I thought they chose the oil based products because they last longer and would not show white between the boards if the boards separated a little with changes in humidity and the time of year. Would you recommend covering the air conditioning return ducts? Or just leaving the AC off? We live in Tx. Thanks for your assistance.

A: I’m not really sure what is going on here. Oil based finishes do stretch a bit when the boards shrink. I’ve seen this sort of thing in Toronto where floor companies use lacquer as a fast dry base coat. I’ve not seen it happen when several coat only of solvent or oil based poly are applied to the floor. I believe the floor is going to have to be done again from scratch. the guys need to take moisture readings of the floor to make sure it is dry within limits of about 7-9%. Is there a crawl space under the floor?

I think I would keep the house temperature to around 70F or so while the work is being done. When they are ready to start applying finish coats I would shut it off until the finish has set. 3-5 hours. There are so many factors that can influence this job, without being there I am having a bit of a problem knowing what exactly is going on. This is why, after 40 years, every job still makes me tense.

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