Most often associated with engineered hardwood flooring systems, de-lamination is one of the most common repair issues that my company fields. 90% of the time de-lamination is associated with ply constructed materials; however, occasionally some of the softer species (Douglas Fir, Pine) will develop this issue along the spring grain of the floor boards.
Engineered hardwood flooring systems are constructed from a number of “layers” of, typically, Birch, backer with a single layer of hardwood adhered to the top of the board. De-lamination is caused by exposure to excessive moisture which causes the real wood top layer of veneer on the engineered board to swell and separate from the under layer of the ply system (see photos).
Generally, if the source of the excessive moisture is located and repaired, de-lamination is contained to a relatively small area. Unlike cupping, de-lamination is almost always caused by topical moisture introduction. This is good because de-lamination damage can usually be fixed by just replacing the de-laminated boards. Cupping, on the other hand, will require moisture abatement and, possibly, refinishing.