Dupont®, the maker of Stainmaster® carpets, is one of the largest carpet manufacturers in the world. The information stated below is from the Stainmaster® warranty.
"When vacuuming no longer removes all of the soil, or you have not been able to remove stains following the Dupont recommended carpet care and cleaning procedures, it’s time to have your carpet cleaned by a trained and qualified professional cleaner. A reputable professional cleaner knows the latest information on carpet construction, carpet care products, and safe, effective cleaning methods to help maintain carpet beauty. For this reason, we recommend, and our warranties require, periodic professional cleaning. We recommend professional cleaning at least every 12 months.”
It makes sense that regular vacuuming and prompt clean up of spills is important for routine carpet maintenance. But why do manufacturers' warranties also require annual deep cleaning by a professional carpet cleaner?
That's because of two destructive forces that normally affect every carpet - "soiling" and loss of "texture".
Soiling is the build-up of dirt particles and other similar materials that cling to your carpet's fibers. Despite regular vacuuming, these particles and materials accumulate within the carpet pile and result in a gradual dulling of the carpet's color. It takes deep extraction cleaning with powerful equipment and quality cleaning solutions at least annually to remove this accumulated material.
Professional hot water extraction, or steam cleaning, greatly improves the texture of carpet tufts by relaxing and raising matted-down fibers. The Stainmaster® Limited Texture Retention Warranty states the following:
“Hot water extraction to refresh carpet texture, performed by a trained, qualified carpet care professional, is required at least every 1½ to 2 years for coverage under this warranty. Please keep your receipts for proof of service.”
Another important aspect of proper professional carpet cleaning is that it leaves no residue. In the past, carpets were shampooed using a rotary floor machine then left for days to dry. This process left a sticky shampoo residue that only attracted more soil, which eventually caused the carpet to wear faster. Proper cleaning today, however, utilizes powerful extraction equipment to remove all soap and detergent residue as well as over 95% of the water used in cleaning. The carpet is rinsed with hot water along with a special cleaning agent to leave the carpet in the proper pH state.
The use of small rental machines therefore is highly discouraged. These machines leave a soapy residue, which only attracts soil. In addition, because of their inability to effectively remove the water used in cleaning, multiple cleanings can lead to carpet delamination, where the layers of carpet separate and the top layer develops unsightly rolls or wrinkles.