So the carpet cleaner leaves your house and all the spots are gone. However, the spots come back later. Has this ever happened to you? Well hopefully the carpet cleaner took pride in his work and came back out and fixed it for you, but why did it happen? Here are three scenarios in which spots sometimes reappear. These typically happen either right after the carpet is dry or slowly reappear a couple of weeks after the spot was cleaned.
In the first scenario, a spot reappears as soon as the area is dry. When this happens, it means the soil that was deep down in the bottom of the fibers or in the backing was not completely removed. Only the surface or top of the fibers were cleaned. As the fibers dried the soil from down below wicked its way to the top and was left as the water evaporated. If your carpet cleaner redoes the area using fresh water and then dries it quickly, it should fix the issue.
The second scenario would be when a spot reappears in the same area as a spot that was removed a few weeks before. This generally occurs because a spot remover product was used to remove the spot originally and it was not rinsed out with fresh water. This situation is generally not caused by the carpet cleaner, but by the homeowner doing spotting themselves. The detergent residue from the spotting, will not dry totally and will stay sticky enough to become a dirt magnet. So every time someone walks on the spot, soil is instantly stuck to the top of the fiber. Also, any dust in the air will be attracted to the spot. Then the spot appears to come back, when in reality it is new soil that is stuck in the detergent residue. This is why it is important to flush any spot after you treat it with plenty of fresh water.
The third scenario would be when the spot starts out as tape or some other sticky residue. This usually happens if plastic with a sticky residue is stuck to the floor covering either during a remodeling project or tape stuck under a rug to hold it in place. Whenever the plastic or tape is removed some of the sticky residue will remain on the tips of the fibers. As soil is tracked across the area, it sticks to the tops of the fibers. It is possible to remove the soil out of the sticky residue and not remove the residue. If this happens, then over the next few days or weeks the fibers will start to attract soil again in the same area. Usually a solvent is required to break up the sticky residue followed by a fresh water rinse. For this situation you might consider calling a carpet cleaner to properly remove the sticky residue.