Hey everyone I just signed up for the forum. I have a hardwood floor on the 35th floor of a condo (on concrete) that is buckled and warped heavily in one specific area and very lightly warped and separated throughout. The condo is electric heat. The floor was installed approximately 2 months ago and showed signs of this damage about a month afterwards. From what I know the air was not after the installation (the unit was vacant). It's all windows from one side so the unit gets hot. I can understand the slight separating in the main area because of humidity and temperature differences, but the floor in the narrow kitchenette hallway was heavily warped/bulked and stained black. A removal of the floor found that the there was no moisture below the moisture barrier, but on top so the source was not the concrete moisture. We checked for any mechanical leakage and used moisture meters and found no signs of moisture leaking from above. From what I know the floor was acclimated about 2 weeks. But doesn't it take a while for it acclimate once installed? you can't just turn off the air can you? It will absorb the moisture, no? But would it be enough moisture to cause black staining between the floor plank and moisture barrier? Any thoughts? I' tried to attach pictures but I keep getting an error saying they don't know the image dimesions. Maybe this link will work https://drive.google.com/open?id=0B-vt5 ... S01c2lrUGc

It looks like your floor got wet with water at some point. I have never seen mold grow on wood that is less than 19 percent moisture content. When it dries the mold stops growing. This is not an acclimation problem. The slab was cured before installation was it not? A wet slab can give off lots of water vapor which will swell the wood above it. If it was not well cured and gave off moisture when curing the vapor will be absorbed by the flooring. When it dries from being in the bright sun out there will be cracks or gaps between strips. Just because the was a"moisture barrier" installed it won't protect from moisture vapor. The water had to come from somewhere. A sealed building where the air has not been conditioned will magnify the problem.