One of the most frustrating things a customer can experience is seeing a stain reappear after a carpet has been professionally cleaned. The carpet looked perfect when the cleaner left, but the following day the stain seems to have returned.
In many cases, this is caused by a perfectly normal process known as wick-back.
What Is Wick-back?
A carpet is much deeper than its surface. Beneath the visible fibres are the backing materials and, beneath that, the underlay.
When a liquid such as coffee, tea, red wine or pet urine is spilled, it often penetrates deep into these lower layers. Even after thorough professional cleaning, tiny amounts of staining can sometimes remain beyond the reach of the cleaning equipment.
As the carpet dries, moisture naturally moves upwards towards the surface. If it passes through these remaining contaminants, it can carry them back into the carpet fibres, causing the stain to reappear.
This process is known as wick-back.
Does It Mean the Carpet Wasn't Cleaned Properly?
Not at all.
Professional cleaners work hard to remove as much contamination as possible, but some spills penetrate so deeply that complete removal during a single visit may not always be possible.
Wick-back is particularly common with older spills that have been left untreated for some time, or where large volumes of liquid have soaked into the carpet and underlay.
It is simply a consequence of the way carpets dry.
Can Wick-back Be Prevented?
Professional cleaners use several techniques to reduce the likelihood of wick-back.
These include thorough extraction to remove as much moisture as possible, appropriate stain treatments and, where necessary, using air movers to speed up drying. Faster drying gives moisture less opportunity to carry remaining contaminants back to the surface.
Even so, no professional cleaner can honestly guarantee that wick-back will never occur.
What Should You Do If It Happens?
If a stain reappears after professional cleaning, the best course of action is simply to contact your carpet cleaner.
Reputable companies expect the occasional wick-back and will usually return to carry out further treatment if required. As the stain has now migrated to the very tips of the carpet fibres, a cloth dampened with a cleaning solution is all that is needed to remove it.
Understanding a Reappearing Stain
A reappearing stain does not necessarily mean that new dirt has entered the carpet. It can be remaining contamination moving upwards as moisture evaporates.
Fortunately, it is also relatively uncommon, and when it does occur it is usually straightforward to correct. The important thing is not to assume the carpet has become dirty again or that the cleaning has failed. Wick-back is simply part of the drying process when contamination has penetrated deep into the carpet.