What causes black, sooty edges around carpets? Dark, dirty lines around baseboard edges on carpeting is caused by filtration soiling. This has to do with the HVAC system and how the forced air comes into the room at a higher speed than it can leave. Instead of trapped air leaving through the ventilation system, it will try to leave the room between cracks along carpet and baseboards, along stair treads, or seep underneath doors.
Air that is forced into the room at a faster rate than it can escape sets up ideal conditions to allow dust and carbon particles to settle down along the edges. Because there is no carpet padding at baseboard edges, air can more easily push through those areas, leaving behind lines of black carbon stain. This carbon is more than dust and comes from candles, gas furnaces, pilot lights, cigarette smoking, fireplaces, gas hot water heaters, and even incense! Are you a heavy user of candles and incense? You should know that candles are the biggest culprits for causing black lines around the edges of the room!
In newer homes, builders caulk or install barrier materials between the wall and the bottom of the sill plate. This reduces air leaks and drafts from underneath baseboards. Older homes do not have this extra layer of protection and are more prone to black line stains.
To help prevent black lines, dust baseboards more regularly and vacuum carpet edges with a vacuum cleaner equipped with an edger attachment. Replace air filters monthly. You may also want to consider caulking around floor trim using a clear silicon caulk to minimize drafts.
Black sooty line stains in carpets are time consuming and more expensive to remove than cleaning a room of carpet. Even using a chemical made specifically for soil filtration, the lines are difficult to remove. Removing black lines from carpets is a multiple step process that must be done by hand, and often requires specialty equipment and chemicals. After vacuuming edges, a chemical especially formulated for this carbon-based stain is sprayed onto the dark lines and allowed to soak in. Then using a specialty brush, or brushing by hand, the carpet technician scrubs the chemical into the carpet fibers along the perimeter of each room. Using truck mount equipment, the technician extracts the dirt, water and chemicals out of the carpeting.
Call for a free in-home estimate if you need help removing black lines from your carpets.