What is the black line at my baseboards?

One of the most common issues we deal with as professional carpet cleaners is an issue called "filter fading" or "filtration soiling." Filter fading or filtration soiling is the name given to the accumulation of carpet soil found along the edges of wall to wall carpet, as well as under some doors and furniture. It is formed by air movement through the carpet at these different locations. Your carpet acts like a filter and traps the soil from the air. Over time these soils can solidify, permanently staining the carpet. In some cases these soils can oxidize (bleach) the color from the carpet. We see this happen at the base of walls, on stair cases, around furniture, and under doors that stay closed alot. Some houses seem to be more prone to it then other houses. While it is more noticeable on light colored carpet it can still occur on a darker colored carpet, it just may be less noticeable.

It can also be found around walls that are common to a return air plenum. If this is the case and you look inside the return air behind the filter and you see studs here is what you do. Take some sheetrock or plywood and cover the studs on the walls. Then take some caulking and seal all the joints well. This will force all the air coming in the return to go through the filter. Now you can clean the carpet around the walls and it should not occur again in this area.

Complete removal can be difficult or impossible if the problem has been occurring over a long period of time. However, if it is caught early enough it can usually be removed by a reputable carpet cleaning company. The bad news is that a cleaning may take care of it now but unless you correct what is causing it to occur then it will come back.

The best thing to do to minimize this is to vacuum these areas often and have your carpet cleaned often. This is the best way to stay on top of it. If you are replacing your carpet with new carpet and do not want to have the same issues, then after the old carpet is removed you can caulk the area between the subfloor and the bottom of the wall. This will prevent air from being pulled through the carpet fibers up into the wall. Then the soil will not accumulate there. However, it will not prevent it from occuring under doors or furniture.

Kevin Pearson is a Master Cleaning Technician #19267 with the IICRC and has been in the cleaning and restoration industry since 1992. Kevin has worked on the committee that rewrote the carpet cleaning standards and the standard for carpet inspectors. He also serves on two other committees at the IICRC and is on the Board of Directors of the IICRC and the Professional Cleaning and Restoration Alliance. For information Call Pearson Carpet Care at 281-548-7200 or visit our website at www.pearsoncarpetcare.com.