Have you ever had your carpet professionally cleaned, only to notice that some areas seem to look brown after the carpet dries? It is easy to assume that something went wrong during the cleaning, but in many cases, the cleaning did not cause the problem. It simply brought to the surface something that was already deeper within the carpet.
There are two common reasons why this can happen.
The Most Common Cause: Wicking
The most common reason for carpet to appear brown after cleaning is wicking.
When carpet is heavily soiled, not all of the soil can necessarily be removed in a single cleaning. A professional carpet cleaner may make several passes over a heavily soiled area, and each additional pass can remove more soil. But there is a practical limit to how much moisture you want to put into the carpet.
After cleaning, the carpet fibers at the very top dry first because they are exposed to the air. As that moisture evaporates, moisture remaining deeper in the carpet begins moving upward toward those already-dry fibers. This movement of moisture through the carpet fibers is called capillary action.
If that remaining moisture contains dissolved soil, the water can eventually evaporate at the tips of the fibers, while the soil does not evaporate. Instead, the soil is left behind on the fiber tips.
The result can be a brownish appearance, particularly in the areas that were the dirtiest to begin with.
This is why you may sometimes see browning develop after a carpet has dried rather than immediately after it has been cleaned.
There Is a Limit to How Much You Should Clean a Heavily Soiled Carpet
This creates an interesting situation for a professional carpet cleaner.
You know that another pass over a heavily soiled area may remove additional soil, and you naturally want to do the best possible job. But every additional pass also introduces more moisture into the carpet. Eventually, that moisture can penetrate farther into the backing.
That becomes especially important when carpet is being cleaned under conditions that make drying difficult. A humid environment, poor ventilation, or a finished basement with little air movement can all increase drying time.
The longer the carpet remains damp, the greater the opportunity for a musty odor to develop, particularly when soil and other organic material remain within the carpet.
So professional carpet cleaning is not simply a matter of continuing to clean until the carpet looks perfect while wet. An experienced technician has to balance soil removal with how much moisture is being introduced and how quickly the carpet can realistically dry.
The Second Cause: Cellulosic Browning
The other common cause of browning is something called cellulosic browning.
Some carpets contain plant-based fibers such as cotton or jute in their backing or construction. These materials contain cellulose. When they become sufficiently wet, they can release a brown-colored substance that can migrate toward the surface of the carpet as the carpet dries.
The result can look very similar to soil wicking.
The important difference is that this browning is not simply dirt that was left behind in the carpet. It is coming from the cellulosic material used in the carpet’s construction.
The Best Way to Prevent the Problem Is Good Carpet Maintenance
Although both of these situations can occur for different reasons, there is an important lesson here: the more soil that accumulates in a carpet before it is professionally cleaned, the greater the potential for problems.
That is why regular vacuuming is so important.
I learned just how much soil a carpet can hold even in a very clean home when I purchased a Kenmore canister vacuum with a powerhead that had a soil sensor. As I vacuumed, the sensor would turn red when it detected particles being picked up. As I made additional passes over the same area, the light would sometimes turn green, then red again, and eventually remain solid green.
That told me that I was finally getting very little additional material out of that section of carpet.
I found that a bedroom might require only a couple of passes in lightly used areas, while a hallway could require four or five passes before I had removed as much loose particulate soil as the vacuum could reasonably pick up.
And this was in my own home, where we did not wear shoes indoors and kept the house very clean.
That experience gave me a much better appreciation for how important thorough vacuuming is. Vacuuming is the first line of defense in carpet maintenance.
But Vacuuming Cannot Remove Everything
Even with good vacuuming, there are types of soil that will remain in the carpet.
Body oils and perspiration from bare feet, oils from pets, fine particles associated with cooking, and other soils can become attached to the carpet fibers and cannot simply be vacuumed away.
That is where professional cleaning becomes important.
A good maintenance program combines regular, thorough vacuuming with periodic professional cleaning. The appropriate cleaning frequency is different for every home. A household with several children and multiple pets is obviously going to have very different carpet-cleaning needs from a home with one child and no pets.
The rooms in the house matter too. A family room or hallway may need attention much more often than a formal dining room that is rarely used.
There can also be reasons to clean carpet that have nothing to do with whether it looks dirty. Carpet can collect dust, pollen, dander and other particles, and some people are more sensitive to these contaminants than others. For that reason, a bedroom that is occupied for eight hours a day may deserve more frequent cleaning than a room that is seldom used.
So, Why Did My Carpet Turn Brown After Cleaning?
In most cases, the answer comes down to wicking of soil that remained in the carpet or cellulosic browning from plant-based fibers in the carpet’s construction.
Neither one necessarily means that the carpet was damaged by professional cleaning.
In fact, sometimes the cleaning simply reveals a problem that was already present: too much soil had accumulated in the carpet, or the carpet contained materials that were susceptible to browning when wet.
The best way to reduce the chances of this happening is simple: vacuum thoroughly, don’t allow soil to build up for years, and have your carpet professionally cleaned at a frequency appropriate for your particular home and lifestyle.
After more than 55 years in the carpet cleaning business, I have found that there is no single cleaning schedule that works for everyone. Every home is different, and the right maintenance program depends on how that home is actually used.
— Alec Houle
Alec’s Carpet & Upholstery Cleaning LLC
781-871-1415