I want to explain the reasons why using a steam mop on your hardwood floor is very destructive and how doing so can cost you more in the long run.
Wood and Water Don't Mix
Have you ever left a piece of wood outside that got rained on? What happened to that piece of wood? Most likely it may have seemed okay for a day or two but then it started to cup and curl and not look very straight. When steam mops are used to clean hardwood floors, moisture is forced into the wood, causing your hardwood floors to react like the piece of wood left in the rain. The floors will cup and warp because it is taking in more moisture than it can handle.
Steam Mops Break Down the Finish
Another reason not to use a steam mop on your hardwood is that over time it breaks down the finish on your floor. How? Well when you run a steam mop across the floor, the machine is continually pumping out steam and forcing it into the floor's protective finish. This combination of moisture and heat eventually break down the finish leaving the floor unprotected.
Leaving the floor unprotected can cause permanent damage. This damage could include the boards turning a grayish colors because of the reaction the wood has with the water, as well as board needing replacing.
To help prolong the life of your floor read this blog post. My suggestions on how to clean your floor is to sweep, dust mop or vacuum (soft bristle end no beater brushes running) regularly, and then clean the floor with a neutral PH hardwood floor cleaner. Not all hardwood floor cleaners are created equal and some have fillers in them that leave a residue on the floor. Overtime these fillers build up on your floor making it slick and dull looking. One of the best hardwood floor cleaners out there that I use and recommend is made by Pallmann. Its non-toxic, streak free and has a lemony smell. This cleanser will also leave no residue behind.