The solid wood board has a tendency to become convex so that it rises in the middle of the board, or concave so that gaps occur in the longitudinal joints. This tendency to become convex or concave is a major disadvantage when sanding the boards. Unnecessary amounts of wood have to be sanded away to achieve a flat surface. The claim that a solid wood board can be sanded more times than a multilayer board is not always true.
The multilayer board is dimensionally stable, which minimises the risk for cupping or dipping. The floorboard remains plane. The flooring can be sanded without removing unnecessary amounts of the surface. A multilayer board can therefore be sanded several times, just like a solid wood board.
New generation floorboard
A solid floorboard is 100% wood. That used to be the only type of floorboard available. The multilayer board is constructed of several layers of wood, which presents a range off technical benefits in terms of form stability.