How wood flooring
Wood is a living element, and as such it is sensitive, constantly reacting to the surrounding environment. It is especially sensitive to changes in humidity and up to a certain point it adapts, adjusting slowly and imperceptibly through a series of movements which, over the long run, change its dimensions.
It’s easy to see how this natural response might be a problem when it is used for flooring, which is regularly subject to great shifts in temperature over large surfaces, not to mention often wet. Research has, thank goodness, offered solutions to this problem. With the advent of more stable modern engineered parquet, wood and safety can finally get along.