How do you flatten raised laminate floor?
It may have raised because insufficient expansion area was left around the perimeter when installed. Remove a baseboard and check to see if at least a 1/4″ gap exists between the flooring and the wall. If the flooring is touching the wall, it will need to be trimmed down to allow for the expansion of the material. This may involving cutting the material in place, a messy job that should include a shop vac to suck up the dust when cutting.