Since we have recently been called out to repair some wood floors damaged by using a steam mop to clean, I decided to post this question. Below is an answer to the question by the National Wood Flooring Association magazine:
"Everyone has seen the commercials showing a steam cleaner magically sanitizing, disinfecting, deodorizing, and cleaning a wood floor. But that doesn't mean that wood flooring manufacturers or finish manufacturers think steam cleaners are appropriate for a wood floor; in fact, some have begun to specifically mention steam cleaners in their list of don'ts. Inspectors are also starting to come across floors that appear to have been destroyed by repeated steam cleaner use. Peeling finish, whitening finish and cloudy finish are just some of the side effects being reported by people looking at floors after steam cleaning. In general, the oft-repeated industry saying "Water and wood don't mix" holds true. Unless the wood flooring or finish manufacturer says it's OK, it's safest to assume steam cleaning is a no-no on a wood floor."