Should you use steam cleaning on hardwood floors? Absolutely NOT and here’s why…
Humans will experience third-degree burns if exposed to 150°F for two seconds or more. If you’re steam cleaning a wood floor, you’re exposing the wood and the finish on it to temperatures at least 60°F higher. How anyone can see this process as safe for the wood or the finish is beyond me, and yet, here we are.
Let me count the reasons:
First and foremost, there isn’t a single manufacturer of any wood floor products (stain, sealers, finishes, solid tongue and groove flooring, solid plank, engineered and prefinished flooring, wood fillers, etc.) that recommends or endorses this cleaning process. Furthermore, the National Wood Floor Association doesn’t either. In addition, a number of manufacturers will void their product warranty if you use a steam mop on their product. Finally, follow this link to read a timely Consumer Reports article entitled Why You Shouldn’t Use a Steam Mop On Wood Floors.
A second reason is the sloppy and incoherent advice being offered by manufacturers of steam mops. Several tell you to only use it on wood floors that are “well-sealed”. Ok, just what do they mean by ‘well sealed?’ One manufacturer said if you put a drop of water on the wood floor and it retained its shape, it was ‘well sealed.’ Another said that if you rubbed your finger over the surface and it didn’t leave a smudge, it was ‘well-sealed.’ The third customer service tech just said all wood floors are ‘well-sealed,’ so don’t worry about it. No mention of how many coats of finish, type of finish, age of finish, or any other relevant information that might need to be taken into consideration. As I said: sloppy, incoherent, and let’s toss in naïve for good measure.
Third and perhaps the most compelling reason for not using this process is the impact hot moist air has on the finish. For manufacturers of coatings, the easiest way to test the long-term performance of coatings is to accelerate their aging. You accelerate the aging of coatings by heating them up, then cooling them down. By getting them moist, then drying them out. Let’s compare this to cleaning a floor with mop belching 212°F hot air. You’re heating it up and then cooling it down. You’re getting it moist and then drying it out. I’m seeing a pattern here!
Under normal conditions, finishes will naturally begin to develop micro-fissures and microscopic cracks on their surface from the normal expansion and contraction over time. The surface gradually becomes more brittle and eventually will begin to show wear more easily if not protected with new coats of finish. There is nothing about steam cleaning a wood floor that is normal and it accelerates the aging of the finish. By accelerating the aging of the finish, you will likely experience wear and performance problems much earlier than you normally would. So the question to be asked is: why would you take any finish and accelerate its aging? The finish is there to protect the wood and why you would compromise this protection by accelerating its aging makes no sense at all.
Documentation:
But enough with the science – let’s find some proof of damage from steam cleaning! Kim Wahlgren, editor of Wood Floor Business and Roy Richeow of National Wood Floor Consultants were kind enough to supply me with some photographs of damaged floors. They confirm why there is absolutely no support for this particular cleaning process within the wood floor industry. The route to damaging most floors usually starts in the soft cell tissue which is in the grain pattern of the wood. This area is more vulnerable and if compromised, will easily allow moisture to penetrate into the wood at a much faster pace. The wood in the soft grain is often described as being “straw-like” and this expedites the distribution of water into the surrounding and more dense wood. In the photo below pulled from Wahlgren’s article, you can easily see that the finish has been compromised over the soft grain tissue and shows discoloration. You can also see where patches of finish on the adjacent dense graining are flaking off as the moisture expands from the graining.
In the second picture, the use of a steam mop has resulted in the loss of soft tissue of the wood grain. The third photo shows where the wood is shedding its protective coating. These situations will not get better.
The last photo is by far the most dramatic as it shows catastrophic failure from steam cleaning a handsome pine floor with a urethane finish that is only around thirty years old. As I mentioned before, the aging process of finishes creates very fine cracks over time (these would not be visible to the naked eye) which allows moisture to easily flow into the wood. Since wood is a natural organic product, it is highly reactive to moisture and will start expanding and contracting more violently with excess heat and moisture. This can decrease the strength of the cell structure, dramatically altering the performance and resilience of the wood and its finish.
Summary:
In conclusion, I am rebranding steam cleaning wood floors as scalding the surface because that’s exactly what you’re doing. It is an extreme, radical, and destructive approach to wood floor maintenance that accelerates the aging and deterioration of the finish. The kindest thing I can say is it is absurd. For the last twenty years, I’ve been recommending the use of cleaning products made by the manufacturers of wood floor coatings. These manufacturers know the finishes and wood being cleaned and have the best interest of these two materials in mind. A lot is riding on how well your finish protects and beautifies your wood floors and scalding them will accelerate their demise. Steer clear of this misguided approach to wood floor maintenance!
Michael Purser
Rosebud Co.
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