There are a few reasons why spots come back after steam cleaning, and even sometimes after professional cleaning. The most common persistent spots are due to something called “wicking.”
What is “Wicking?”
When fabric is left in liquid, the liquid travels up the fabric to the top. If the liquid is colored (like in a stain) eventually, the top of the fabric absorbs the liquid and shows the color. Most kids will do this as a science experiment in elementary school either by placing a candle wick, strip of cloth, paper, or celery into a cup of water with food coloring. As neat as this is to watch, it is the opposite of what we want in our carpet.
How do carpets “wick” stains?
The stain has to settle deep into the backside of the carpet or in the padding below the carpet to create this stain problem. When the stain is that deep, even after the carpet is completely cleaned, the fibers of the carpet will wick the stain from below and bring it back to the surface.
Stains that cause wicking problems are stains created by a large amount of liquid that cannot be quickly or fully removed before they soak the backside and/or pad below the carpet. One common type stain that creates this issue are pet urine stains, since they are often created by higher amounts of liquid and are not found immediately. Cleaning these stains often makes it worse, since most people add more liquid through the form of cleaners in an attempt to spot clean. The additional liquid allows more of it to soak into the backing and padding, or even spread and become larger.
How to prevent and clean a “wicking” stain:
When it happens, the best thing to do is to remove as much liquid as possible using towels and fans. Be careful and sparing when using a liquid carpet cleaner. A wet-dry vacuum can help remove larger amounts of liquid. In the end, the only real solution is to have the spot professionally cleaned. High quality professional cleaning companies can add enough water to sufficiently dilute the stain and remove enough water from deep within the carpet that the stain is removed and does not come back. With very bad stains, a single cleaning, even from the most reputable cleaning professional, may not be enough to fully remove the stain.
We are here to help. Just remember to let us know that you have a stain that comes back after steam cleaning so that we can properly treat it.