Are 2 layers of poly enough or should I have him add a 3rd?

Q: I am having my hardwood floors redone. They are parquet and have been carpeted since the house was built in 1957. I want to stain them also and the contractor will include 2 layers of Poly in the quote. My question is: are 2 layers of poly enough or should I have him add a 3rd? How many layers of polyurethane?

A: 2 Coats of polyurethane is what I would call “rental level”. A bit of explanation is in order. I don’t live in Toronto anymore but that is where I spent a large part of my flooring career. In that area the use of lacquer sealer as multiple initial coats prior to apply the poly was the norm. Terrible way to finish a floor. When I went on my own I would apply 3 coats of polyurethane. Architects would probably recommend the first coat is cut with 10% mineral spirits. If your floor guy is using solvent based coatings, 2 straight coats of polyurethane is good, but not the best. They should go an extra coat. I have used Poloplaz coatings for several years. They have a polyurethane based sealer as does Dura Seal which penetrate into the floor very well, somewhat as the architects would achieve by cutting straight polyurethane. Then apply 2 coats on top. Regardless of which finish they use on top of that you should end up with a pretty tough coating.

Related Q: I have a question about a project we recently did. We sanded our wood floors down and applied polyurethane. We used the professional formula from minwax. So with coats 1-3 the floor looked great, it was shiny like glass. That’s the look we were going for. We originally wanted to do 5 coats because the floors we are doing are actually classrooms, high traffic areas, but after the 4th coat the floor was not shiny. The shine was gone. Could you tell me what happened? What should we do to bring back the shine?

A: To be honest, I don’t know what happened. I don’t generally recommend piling on multiple coats, one after another after 3 coats. Are you sanding between coats? When you can rub it with fine sand paper and the finish powders apply another coat and leave it at that. Make sure the dust is all vacuumed up and I always wipe the floor down with a micro fiber mop. Generally the spread rate is 500 sq. feet per gallon. This coats are always better than thick ones. Is it possible the batch you used for the last coat was not gloss? Maybe it was mislabelled. Semi and satin will have a paste in it and looks much different in the can compared to gloss.