Why did brown spots appear on my carpets after they were professionally cleaned?
Sometimes after a carpet is cleaned professionally some brown spots may appear. These spots can be the result of water not being sufficiently extracted during the drying process. Do not be hasty to think that too much water was used. In fact the appropriate amount of hot water may have been used, but if it was not extracted properly it can cause browning. The browning can be caused by the water wicking up the carpet fiber as it dries, carrying with it soil from the carpet backing and the pad. This is similar to oil being drawn up an oil candle wick.
Another cause in older carpet is the wicking up of tannin stains from the jute backing. Many older carpets have a backing made from jute fiber. This is the same type of fiber that crafters use to made macramé projects. Jute fiber is a vegetable (cellulose) fiber and like tea, bark and other plant fibers is naturally infused with vegetable dyes known as tannins. The tannin can rise up through the carpet fibers as they dry if water was not extracted enough to prevent wicking.
Your carpet may look perfect when the carpet cleaning technician finishes his job, but spots may appear after they have left. This browning affect is however easy to correct. Your cleaning technician can return with a clean cotton towel and anti-browning solution, this will quickly remove any browning.
To insure that carpets do not develop this cellulosic browning, your carpet cleaning technician should do extra drying passes over the carpet. The carpet should also be raked with a carpet rake. Carpet raking lifts the carpet pile, allowing it to dry faster and leaves the carpet fluffy instead of matted and crushed.
At Hydro Clean Carpet Cleaning in Colorado Springs, CO our technicians are trained to perform extra drying passes over the carpet with the carpet cleaning tools. The extra drying passes should be done slower than the cleaning passes. Some other companies do wet passes only leaving the carpet soaked. When this happens, total drying times will be counted in days, not hours. To aid in drying, we will often use drying fans (air-movers) on one room while we clean the next.
Be sure to ask your carpet cleaner about drying times and their guarantee if browning or other stains should appear after cleaning. Ask whether they are using a truck mounted carpet cleaning system or a portable. A truck mounted system will have more lift and airflow to remove more water than a portable unit will. Ask if they are willing to use air-movers to speed drying. Even if air-movers are used, windows should be opened and ceiling fans turned on.