Moisture ratings

Q: I am having hardwood laminate installed over radiant heat. The tubing is installed in a grooved plywood track on top of the sub floor. The maximum inlet temperature into the loops is approx 108 degrees. There is a 20 degree temperature drop so the flooring will only see about 88 degrees.

The flooring as I understand it has a moisture rating of between 8-10. My heat designer said they recommend between 6-8. I have the new flooring laying on the radiant heat (in boxes) for about a week.

I don’t completely understand the moisture ratings but do you forsee any problems with this installation as far as expansion and contraction?

A: I don’t think you will have a problem, but if it was my job, I would probably contact the product manufacturer, or check their web site. They may very well have a data sheet giving all the needed statistics.