Deep Cleaning Carpets Can Minimize Wicking

While encapsulation and the use of absorbent compounds are popular low-moisture interim carpet cleaning techniques that can help control soil wicking, they are not a replacement for regular deep cleanings.

Mervicker recommends hot water extraction to thoroughly remove dirt trapped in the base of the carpet. Before extracting, distributors stress the importance of vacuuming the area thoroughly and using a prespray, allowing a dwell time of 10 to 15 minutes.

If custodians do a good job of suspending the soil with a prespray, they won’t have to use as much water to flush it out of the carpet during extraction.

“If I didn’t use a prespray, and I come in with a wand and detergent in the water and go over the carpet quickly, the detergent won’t be able to pull all that dirt out,” says Yeadon. “So you have to make more passes with the wand — meaning more water and longer dry times.”

Along with excess water, using too much detergent when extracting can contribute to soil wicking. To avoid overuse of chemicals, custodians should follow directions for dilution ratios.

“A common mistake that causes wicking is not following directions when mixing the chemicals,” says Mervicker. “If it says use one ounce per gallon, they use four or five ounces per gallon, thinking that will get it cleaner, but it actually makes it worse. You have more residue left in the carpet, and that residue attracts and holds dirt.”

Some departments favor a pump-up sprayer to apply the chemical to the carpet, rather than running it through the machine. This can help to control the amount of detergent used. In areas that have a lot of chemical buildup, Thompson suggests a neutralizing product to neutralize and remove alkaline buildup from carpet fibers.

“We’re pushing peroxide-based products,” he says. “They seem to work very well in carpet cleaning equipment. They’re also environmentally safe and they’re a neutralized cleaner.”

Following extraction, experts recommend a second rinse using only water to ensure that chemicals are properly removed. Then, the focus is on drying.

A Dry Idea

Moisture must be present for soil wicking to occur; therefore, carpets should be dried as quickly as possible. Over-wetting carpets should not be a concern if extractors are used correctly. However, if excess water is present, workers can speed up the drying process with the use of carpet fans.

“The best thing custodians can do to dry the carpet faster is put an air mover on it,” says Yeadon. “It blows across the surface and pulls the moisture off the tips of the fibers. As moisture from the tips leaves, the moisture from below is going to come up and take its place. The faster I move that air across the surface, the faster it dries. And the faster it dries, the less chance I have of anything wicking back up.”

Mervicker also suggests running the air conditioning to speed up dry times and extracting carpets when foot traffic is at a minimum.

Experts agree that having a strong carpet maintenance program is the best defense against soil wicking.

“Wicking usually happens as a result of poor carpet maintenance between cleanings,” says Mervicker. “If it’s wicking or turning brown, that’s an indication that you didn’t get all of the dirt out of the carpet either before or while cleaning.”

Experts stress that a strong vacuuming schedule and proper interim maintenance between cleanings will go a long way to keeping carpets looking like new. 

KASSANDRA KANIA is a freelance writer based in Charlotte, N.C.