Carpeting and its maintenance can be one of the largest expenses facing building owners and managers. To make sure they get the most out of their investment, the Carpet and Rug Institute recommends that buyers start with the right carpet choices that lead to the best end-use carpet performance.

containing, removing and properly disposing of unwanted material. This means removing unwanted substances from an environment or environmental compartment. When exposure is reduced, the probability of an adverse effect is also reduced.

• Constant attention to and application of principles of maximum restorative cleaning and minimum residue, especially as they apply to safety, the proper and effective use of chemicals, carpet extraction machines and vacuum cleaners.

• A recognition that carpet care must take all of the following into account, the management of sources of unwanted substance that can get into the carpet; the

• Carpet Maintenance Guidelines activity levels; design of carpet; the environment in which carpet is installed; and ventilation. A consistent management program emphasizes:

• Effective cleaning systems directed at maximum restorative cleaning, minimum residue, safety, and ease of use;

• Cost effective cleaning strategy, plan,schedule;

• Training and recognition of cleaning technicians;

• Periodic inspection, assessment and management review of cleaning programs.

The basic scientific principles of effective restorative cleaning can be divided into five major steps: dry soil removal, soil suspension, soil extraction, pile setting (finishing or grooming), and drying.

Principle 1: Dry Soil Removal (Dry Vacuuming) is accomplished in phases:

• Pile preparation (using grooming tools) is employed to untangle the fiber of high-pile carpet, and must precede dry vacuuming.

• Overall vacuuming with a CRI “Green Label” vacuum cleaner.

• Concentrated entry area vacuuming (removal of the destructive build-up of abrasive soil).

• Vacuuming the perimeter of the room to remove fine dust and soils that can settle in the crevices around the room, causing filtration soiling.

Principle 2: Soil Suspension – Once dry soil has been removed from the carpet, soil suspension (pre-conditioning) procedures begin. Soil suspension and removal are the most critical steps in effective carpet cleaning.

The goal of soil suspension is to separate soil from fiber surfaces. Soil suspension is accomplished by the combination of four things: chemical action, elevated temperature (heat), agitation and time.

Filtration Soiling is a term used to describe dark, grayish lines that may appear around baseboards, under doors, along the edges of stairs, and possibly away from walls where plywood sub-flooring materials have been joined. A technical bulletin can be obtained at www.carpet-rug.com.

Chemical action is employed in two phases of the cleaning process:

• In the first phase, chemicals are used to prepare the carpet for cleaning by reducing surface tension and dissolving various soils. This step, called preconditioning, is essential. It is unreasonable to suggest that soils, which have been ground into carpet, along with oils that have had years to oxidize or dry out, could be suspended adequately in the few seconds that elapse between the application and removal phase employed with restorative cleaning method.

Therefore, remember that pre-conditioning takes time.

The second phase of chemical activity occurs when chemicals are mixed or metered into rinse solutions to suspend light soils that accumulate in non-traffic areas, along baseboards, or under furniture.

Chemicals properly formulated, mixed and applied during pre-conditioning are essential for effective cleaning.

Elevated Temperature (Heat) – Heat reduces the surface tension of water and enables faster, more efficient cleaning than cold water. It is merely a matter of thermodynamics: heat accelerates the molecular activity of chemicals employed, and thus aids in separation of unwanted matter from fibers.

Agitation – Agitation in some form is required to accomplish uniform chemical penetration and distribution. Without agitation, soil suspension tends to be no uniform, which is often indicated by soil streaks following the removal process.

Using a common, multi-bristled brush or comb to work in pre-conditioner chemicals is most effective and time-efficient. Brush agitation refers to the fore-and-aft stroking of preconditioned carpet pile throughout traffic areas, placing particular emphasis on entry, pivot, and heavily soiled areas.

Mechanical agitation involves the use of mechanized rotary or cylindrical, nylon-bristled brush action to achieve aggressive agitation and distribution of pre-conditioning chemicals into the carpet pile.

Time – The fourth fundamental, time, is often the least considered. Soils deposited and compacted over extended periods between cleanings take time to dissolve and become suspended. Pre-conditioner chemicals require prolonged contact or “dwell time” for adequate fiber penetration and soil suspension to occur.

Based on chemical formulation and application temperature, dwell time can vary, usually 10 to 15 minutes. Follow pre-conditioner chemical manufacturer’s label instructions.

Principle 3: Soil Extraction – Soil is an unwanted substance that is foreign to the construction of the carpet. In order to achieve effective cleaning, suspended soils must be removed physically (extracted or rinsed) as completely as possible from the carpet’s pile.

Principle 4: Pile Setting (Finishing or Grooming) – The term “finishing” refers to any procedure that enhances the appearance of carpet beyond the physical soil removal process in order to improve enduser perceptions of cleanliness. Generally, pile setting or grooming employs one of several finishing or pile-grooming tools (e.g., carpet brush or comb) specifically designed for this purpose. Most low loop pile carpet does not require pile setting.

Principle 5: Drying – Cleaning is not complete until carpet is dry and ready to be trafficked. Drying carpet is essential for three reasons:

• First, it is required to return the carpet to use by end-users as soon as possible;

• Second, drying carpet essentially eliminates slip-fall hazards, especially in areas where carpet transitions to hard surfaces;

• Third, rapid drying eliminates the potential for microorganism growth (bacteria and fungi) and associated musty odors, in addition to health hazards that may arise if carpet stays wet in excess of 12 hours.

Adequate natural or mechanical ventilation during the cleaning and drying phases of restorative cleaning will speed drying time. The use of commercial air movers (drying fans), HVAC handling systems, or dehumidifiers greatly reduces drying time. When properly performed, restorative cleaning methods should leave the carpet dry within six to eight hours.

Humidity or environmental conditions may extend drying time, but under no circumstances should drying time exceed 12 hours.

A facility-wide restorative cleaning should take place at least twice a year to remove the accumulation of soil overlooked during daily maintenance. [Note: Inspect heavy use areas for slight dulling of color. This indicates a buildup of soil and requires more frequent restorative cleaning.]

Precautions: During restorative cleaning of carpet, follow several common sense precautions: • Always vacuum first;

• Apply a pre-conditioner, following chemical manufacturer’s label instructions, and agitate into the carpet’s fibers allowing a dwell time of usually 10 to 15 minutes;

• If using a chemical cleaning agent, it is important to use a rinse system to remove any potential chemical cleaning residue from the carpet yarn that might result in a high rate of re-soil;

• Supply natural or mechanical ventilation during the cleaning and drying phases of restorative cleaning. Adequate ventilation is necessary to speed drying time. The use of commercial air movers (drying fans), HVAC handling systems or dehumidifiers greatly reduce drying time.

• Follow directions for mixing solutions carefully. Using a solution stronger than the concentration recommended will not improve cleaning efficiency and may leave behind detergent residue that can lead to accelerated soiling.

• Limit access to damp carpet until it is completely dry to avoid rapid re-soiling.

• Furniture should not be moved back into the room until carpet is completely dry.

Note: If furniture has to be moved back into the room before carpet is completely dry, be sure to use plastic tabs under the legs of furniture to prevent rust or furniture stains from developing on the carpet.

One of the most beneficial features of restorative cleaning is its capability of removing deeply embedded soils. Carpet should always be cleaned according to carpet manufacturers’ specifications. If the manufacturer is not known, procedures should be followed as stated in the Institute of Inspection, Cleaning and Restoration Certification’s Standard and Reference Guide for Professional Carpet Cleaning, S100, (IICRC S100, Revised, 2002).

Many cleaning systems are available; however, their effectiveness varies widely.

When choosing the cleaning system, the important considerations are:

Obtain the carpet manufacturer’s recommendations, if possible;

• It must clean effectively;

• It must not damage the texture of the carpet;

• It must not leave excessive residues of cleaning materials. ❑