Solid Hardwood, Engineered and Laminate Flooring - white spots on new parquet floor (Finishing Wood Floors)

help!! I just installed a parquet floor that had a factory finish on it. Since there were small gaps between the tiles, I steel wooled the surface, and added 3 coats of water base polyurethane on top of it (sanding between each coat). Now I am getting white spots that seem to be under the polyurethane coat, and seem to appear where the floor gets wet. What did I do wrong, and how can I fix it!!!

Some water bases water spot. Some do it more than others. Don't get it wet. If thats all your problems, breathe easy as white spots are also an indication of adhesion failure between the existing and new finish.

If it is an adhesion problem between the finishes, do I need to sand the floors down and repoly? I can spot sand and refinish, if I can be assured at some point that no more white spots will form... perhaps the polyurethane will cure over time? It was a really hot day when I put the finish down, so that may have had an effect too. What would cause an adhesion problem, so I can make sure it doesn't happen again?

If it is an adhesion problem between the finishes, do I need to sand the floors down and repoly? I can spot sand and refinish, if I can be assured at some point that no more white spots will form... perhaps the polyurethane will cure over time? It was a really hot day when I put the finish down, so that may have had an effect too. What would cause an adhesion problem, so I can make sure it doesn't happen again?

Poor adhesion is usually caused by a contaminated surface but could be from a poorly prepared surface. Did you rough it up? Or, if it is an aluminum oxide product, did you use a Tykote system or equivalent to promote adhesion?
IF it is an adhesion problem, you would be lucky if you only had to screen the new poly off. Otherwise, its a complete refinish.

Incompatibility of finish may be the issue. Finish should be sanded off down to raw wood and start from scratch. Gaps between parquet tiles may be due to poor installation, failure to acclimate product to temperature and humidity of the room before installation, moisture issues, lack of vapor retarder, or other reason depending on job site conditions. Application of additional finish coats tends not to resolve gap issues. Although parquet and wood laminate (engineered) floors tend to be more dimensionally stable than solid hardwood, there is still some expansion and contraction (thus the required perimeter expansion gap) and requirements for addressing moisture issues, vapor retarders, acclimation, etc. As wood tends to expand and contract, any finish bond in gaps will tend to break.

For finishing instructions, go to www.nofma.org.

I'm more concerned about...


Steel wool & waterbased finish. Let us know when you start seeing rust marks.

White spots... Lack of adhesion. The finish is lifting when its wet.

Thanks everybody for your advice. I'm guessing it is an adhesion problem, so I probably will refinish sometime down the line (not right away). The spots have only shown up in a few spots, and in mostly inconspicuous places. My question now is this: will the spots continue to show up for the lifetime of the floor (or until I refinish it), or will it get to the point where the poly has cured enough that it won't "un-adhere" anymore?