Cleaning & Maintenance Management Online

More Is Not Always Better

June 8, 2012

We hear the expression "low-moisture carpet cleaning" frequently in the professional cleaning industry.

However, many — especially those in the JanSan industry — are not always sure what low-moisture carpet cleaning is all about.

While carpet cleaning falls under the umbrella of the professional cleaning industry, it is peculiarly considered a separate entity from the janitorial service and supply industry.

Does it mean less water is used in the carpet cleaning process?

Well, yes … and no.

Does it mean more moisture is removed in the carpet cleaning process?

Again, yes … and no.

According to the Low Moisture Carpet Cleaning Association (LMCCA), which is a key main advocate for low-moisture carpet cleaning, the term refers to any method to clean carpets that allows them to return to their natural dry state in two hours or less at 65 percent relative humidity and at a temperature of 70 degrees Fahrenheit.

However, climate conditions and other variables can impact how fast carpets dry, no matter what procedure or recognized low-moisture system is used.

As a result, we may better understand low-moisture carpet cleaning by understanding its goal.

According to Mark Warner, LMCCA president, the goal of low-moisture carpet cleaning "is to reduce the freestanding moisture in carpets [after cleaning], enhancing the carpet''s ability to dry evenly and quickly." Further, Warner says low-moisture carpet cleaning should help eliminate "pool" areas in the carpet where moisture collects as well as other problems associated with excess moisture in the carpet.

Fiber Saturation

Wall-to-wall carpeting in homes, offices and other facilities first became popular after World War II.

Before that, area rugs were typically placed over wood floors or other hard surface flooring.

Although the fibers in area rugs can also be damaged if too much moisture remains after cleaning, because of the drying process involved in cleaning them professionally, this is less of a problem.

The real problem is when excess moisture remains in wall-to-wall carpets.

When wall-to-wall carpets or other types of fabrics such as upholstery are cleaned using water, they can reach a saturation point where they cannot absorb any more water.

When this happens, the additional water becomes freestanding water, as mentioned earlier, and can cause puddles to develop.

This excess water eventually soaks down into the carpet fibers and can also penetrate the carpet''s backing, which means the water can travel down through the padding to the floor below.

This can cause a multitude of problems.

For one, it can damage the carpet fibers so that, even when they are finally dry, their appearance has been altered.

But, the key concern is that mold, mildew and bacteria can develop.

This can negatively impact indoor air quality as well as the health of building occupants.

In many cases, this situation can be rectified with the help of restorative measures specifically designed to remove excess moisture from carpets, such as used in flood cleanup operations.

In other, more serious situations, carpet in the entire area — sometimes the entire room — must be lifted and replaced.

Low-moisture Carpet Cleaning Equipment

Shampooing or using the relatively similar bonnet method were typically the ways carpets were cleaned 50 years ago.

If performed properly, these can be considered low-moisture carpet cleaning methods, according to Warner.

Additionally, the encapsulation method, which uses no water at all, is often cited as an effective low-moisture carpet cleaning method.

But, there can be problems associated with these carpet cleaning methods. The big issue is resoiling.

While little or no moisture is used to clean the carpet with these systems, the chemicals used often leave a residue that attracts more soils to the carpet like a magnet.

In some cases, even when using chemicals that are designed to prohibit resoiling, lack of training by the cleaning professional can still allow it to occur.

Today, these systems are often viewed as "interim" carpet cleaning methods to be used in addition to what has long been considered the most effective way to clean carpets: Hot water extraction.

According to Mark Baxter, an engineer with U.S. Products, a leading manufacturer of professional carpet cleaning equipment, "The extraction method can reach deep into fibers, typically more effectively than these interim methods, removing soils. This improves the health and longevity of the carpet."

But, can carpet extractors that use water also be classified as low-moisture machines?

Once again, the answer is yes … and no.

Carpet extractors were introduced about 40 years ago and were originally referred to as "steam cleaners," according to Baxter.

Early systems used large amounts of water: As much as two gallons per minute.

"If not effectively removed, this amount of moisture can be excessive and cause a variety of problems," mentions Baxter.

So, these early machines would not be considered low-moisture systems unless the excess moisture is somehow removed in the extraction process.

Low-moisture carpet extractors generally use less than a gallon of water per minute and have advanced multi-stage vacuum systems that can better remove the moisture — along with soils — from the carpet during the cleaning process.

"Additionally, some [carpet extractor] systems heat the water/solution," adds Baxter. "This has several benefits. Less chemical may be necessary, making [the carpet cleaning process] greener; the chemicals work more effectively; and they dry faster, the goal of low-moisture carpet cleaning."

According to Warner, not all carpets exist in the same environment.

They can also vary as to construction, installation, traffic conditions, soil types and location.

However, in virtually every situation, a low-moisture carpet cleaning system can be used effectively.

Used properly, a low-moisture system can even reduce cleaning cycles.

"Any way you look at it, low-moisture carpet cleaning is a tool that should be considered by all those who clean carpets," says Warner.


Robert Kravitz is a writer for the professional cleaning industry. He can be reached at RKravitz@RCN.com.