Filtration Soiling is a soiling condition in residential carpet. When walls in a home are not well sealed, they draw air in underneath the baseboards. The air flows under the baseboard and drywall and up the interior of the wall like a chimney. As the air is drawn in it passes through the carpet fibers near the baseboard. Over time, dust, dirt, dander, oils and smoke carried in the air get deposited in the carpet fibers.
    If the carpet fibers near the baseboard are not cleaned regularly and properly, they become dark and eventually the carpet fibers turn black. The black soiling will become permanent if the carpet continues to be neglected. Filtration soiling can also be seen in doorways where air flows under doors. At Hydro Clean Carpet Cleaning, we see this condition most in rental homes and apartments.
You can recognize filtration soiling when you see a solid black line in the carpet right next to the baseboards. When filtration soiling is discovered early, it can be reversed by scrubbing the carpet
Green Scrubbing Brush

with a brush and a spotting solution.  We will typically use a Libman brush with short bristles. When filtration soiling is severe, a professional should be called in to do restorative cleaning. It is tedious work, but very effective.

     Preventing filtration soiling however is extremely easy. Simply vacuuming weekly and using the crevice tool that came with your vacuum will do the trick. Trying to vacuum up to the baseboard is not effective enough because the roller brush can’t reach that close. Just connect the thin long crevice tool and run it along the carpet at the edge of the baseboard. That alone will prevent filtration soiling. In the long term, if you remodel or replace baseboards and trim in your home you should caulk in between the floor and drywall. This will stop the airflow and filtration soiling as well.
Picture carpet cleaning crevice tool 2
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