wood floor in a bathroom


I have recently installed a wide-plank pine hardwood floor in my bathroom. My contractor told me to sand, seal, and then polyurethane it. I sanded and sealed with a “sand n’ sealer.” After re-reading the label for the sealer, I noticed that it said that polyurethane should not be applied on top of it. I am wondering what my options are now. Will polyurethane react badly if applied? SHould I re-sand and start over? Or is it simply easier to use a different finish, and in that case, what finish should I use that will be water-resistant and easy to clean? Is wax ok?

Please let me know.

Thanks, Ines


Dear Ines

I’m really afraid your contractor has made a fatal error, you should not have a solid wood floor in the bath area, and the wide pine plank is just about the worst choice he could have made for you. Wood in damp and wet areas, no matter how many coats of finish are applied will get water damaged. Water molecules are like little octopi, they will slither past the smallest seam, swell the wood and lift the finish, and invite more of their kind in.

That all said, if this wood is more that 4″ wide you should also have followed the instructions on Plank floor installation, as outlined in the Hardwood Authority section of this site. Please read this.

But, I bet by now you are possibly mad at me for suggesting this worst case, and asking for a donation to boot. I cannot help that, I just call them like I see them.

So now that I have warned you of the improper installation, and you still want to go ahead and finish the floor, you guessed it, you have to remove all the Sanding Sealer. This is not the correct first coat for an oil modified polyurethane, and any poly on this wil peel off. This is doubly critical in your case, since you have installed the wood in such a wet area.

So sand the wood to the bare surface, removing all traces of that sealer. And then brush on 5 coats of an oil modified polyurethane, preparing well between coats for maximum adhesion. Read my article on this subject.

Oh, wax is the worst thing to use in such an area, it will simply not hold back the water, and will whiten every time it gets wet. And don’t wax it in the mean time, it will interfere with the sanding AND the finishing with the proper oil modified polyurethane.

As always your Most humble servant, Joseph, the Wood Floor Doctor.