Finishing up a kitchen family room remodel. We had a room divider between the 2 rooms and had it removed so it is now an open space. There was an area under the divider without hardwood about 8 feet long. Also a heating vent was there. The woodfloor guy came in and put in a few planks to fill in the gap between the kitchen floor and the existing woodfloor in the family room. He also added a 2 plank strip that goes the opposite direction of the wood floor as a threshold. Looks great - sort of.
Here is the problem: the family room wood floor now has a very noticeable hump in it going along the planks lengthwise from the new threshold to the center of the room. After finding that we walked on the floor and at the threshold the boards move up and down like there is nothing under them. (Maybe just laid the wood over the heating vent?) The hump is only running from where the divider was to the middle of the floor. In other words: where he did not touch is still flat.
I have already heard grumblings that the floor was that way all along and we never noticed, but that's not true. And the hump combined with his obvious installation problem where the boards move make me think that it cannot just be coincidence that the floor only has problems where he worked.
What could have happened? We still owe the GC tons of $$$ so we are comfortable waiting this out if necessary.