Why Your Wood Floors are Changing with the Weather

If you are reading this article anywhere near where it was written (St. Louis, Missouri) then chances are you have already experienced what the weather can do to your wood floors. If you are new to the mid-west (with our sultry summers followed up by dehydrating winters) or if you are new to wood flooring in your home you may be surprised how the changing of the seasons can change your wood floors.

When we talk about wood floors, what we are really talking about the wood itself; the organic, hygroscopic material that’s kiln dried but is still a product of Mother Nature. Wood flooring will absorb and release moisture through the air (that’s the hygroscopic part) until it reaches a state of equilibrium with its environment. So, essentially, as your home environment changes so does your wood floor. This trend will not dissipate over time and if your home brings on extreme temperature or humidity changes you will be sure to see the results in not just your wood floors but many times in wooden furniture, as well.

Another important note for understanding how wood floors will adjust with moisture or lack of moisture in the air is to think of each board as a stalk of celery. If you look at the ends of celery stalks you will notice all the little fibers inside, this is similar to the individual boards in your floor. The wood floor boards will take in and release moisture through these channels, resulting in powerful and sometimes very noticeable width changes but almost no change lengthwise.

The National Wood Flooring Association (NWFA) gives a great example of how much temperature and humidity affect the dimensions of a hardwood floor. On a 5” red oak solid plank board, if the humidity in the air raises above 65% that board will expand (width-wise) by 0.079”. That doesn’t seem like much until you take into account every board will expand that much. That’s an expansion rate of 1.9” over 10 feet of flooring! Did your contractor leave 2 or 3 inches of empty space at the wall to account for that kind of movement? Probably not. No one would. On that same board, if the humidity falls below 20% we can expect 0.059” of shrinkage. That equates to as much as 1.4” across 10 feet of flooring – the whole room is losing its floor!  

Now, if those numbers don’t impress you, perhaps the photos will. When these floors start moving, nothing – NOTHING – will stop them.

(SEE PHOTOS)

So what does all this mean to you, the consumer? It illustrates the importance of a few things:

Have your AC, furnace, and humidifier checked yearly.  If you don’t have a home humidifier, get one. No, we are not talking about the stand-alone room humidifiers from Walgreens. These are professionally installed units. Time and time again, we see people spending thousands and thousands of dollars on wood flooring, but they won’t spend $400 or so for a humidifier. Make your wood floors look great and last for years with the relatively small investment of a humidifier.

Always be in control the temperature and the humidity in your home or office. If you have wood floors, don’t turn off the air conditioner while you are vacationing in Mexico for a week in July. High humidity rooms, like laundry rooms, that lack sufficient ventilation may not be great choices for hardwood flooring project (talk to your contractor!).

Hire the right contractor. If your flooring guy doesn’t talk to you about the importance of acclimating your wood floors BEFORE installing them, you may want to get a few more bids. He/she should also bring up controlling the temperature while the floor is acclimating. That means your wood floor shouldn’t be acclimating in your garage or sunroom.