Laminate flooring is more than 90% wood. It is a natural product and will always react in direct proportion to the relative humidity of the ambient atmosphere after the installation. Most laminate flooring must be installed as a floating floor system in residential or light commercial installations, with the ability to "expand and contract unrestricted.”
That being said, laminate flooring manufacturers have very clear guidelines designed specifically for expected changes during the life of the floor. Unfortunately, the guidelines are not an exact science; other variables that impact the floor’s expansion and contraction are beyond the control of the manufacturer. But the additional points of information listed here can help to minimize the problems associated with a floating floor system’s limitations as they relate to expansion gaps or joints.