Hi - 2 weeks ago our engineered oak floor warped severely - there was no inclination it was going to happen, we went to work in the morning and by the time we got home in the evening it had warped up by a good couple of centimeters (photo attached). Overnight it moved more and by the middle of last week fumes started to be emitted (which since the weekend have subsided). Our builders came to have a look and suggested that the glue had reacted with something as there were brown spots on the concrete. The underneath of the wood that had risen was wet with moisture/condensation. There was no pool of water or damp patch. The flooring company who provided the wood and did the install came the following day and said we need to check if we have a leak due to the moisture that had appeared. They said it wasn't the glue they used and that they had left enough expansion. The builders have said that 2 layers of damp proof membrane were put down when the extension was being done as they knew we were having underfloor heating and a wooden floor. The floor was laid at the end of last August directly onto brand new screed that had been done in the middle of June. Yesterday we noticed a couple more areas have started to warp - in line with where the first planks rose. What we are baffled with is how water has appeared on top of the screed? We have had no spillages. The main drain for the street runs under the new extension so could that possibly have something to do with it - with the recent bad storms we have had? Our builders are having another look tomorrow and we have a leak detection company coming to investigate for any leaks (but my water bill has come in and doesn't show any increased usage). There was another thread on US houzz similar to our problem and a few specialists had said it was because the glue wasn't applied properly. If anyone has had a similar problem or if there are any specialists that may be able to shed some light on our situation we'd be grateful. Various photos attached. TIA!