Carpet Filtration Lines and How to Get Rid of Them

Brushes, rubber gloves, and cleaning supplies to clean a home for the holidays

You want to keep your carpet clean, but the carpet just keeps fighting back with dark lines running all over the place. If this sounds like your experience, then your carpet probably has filtration lines.

Filtration lines (sometimes referred to by other names: smog lines, soil lines, soil filtration lines, and perimeter soiling) are basically any darkened or overly dirty places in a carpet, normally appearing as black lines or soiled areas at the edges of the room.

They don’t usually appear right away. In fact, it can often take quite a while for filtration lines to appear, but once they do, they typically pose quite an annoyance for most homeowners.

Today, we’re going to explain exactly what causes filtration lines in carpet, as well as how to clean filtration lines in carpet. These little dark spots can be very frustrating, but there is also a carpet care and cleaning solution that exists to fix the problem.

What Causes Filtration Lines in Carpet

Unfortunately, carpets can easily become dirty over time. Certain specific issues, however, can result in much worse stains that people find very difficult to remove on their own, such as filtration lines.

Filtration lines have many causes, but a few are repeat offenders:

  1. Filtration Soiling
    • When filtration soiling occurs, hot and cool air from your central air conditioning travels in the space between your rooms’ walls and floors and transfers extremely small particles along with it, down to the baseboards. These include undesirable elements such as dirt, dust, and even soot.
    • The carpet in a room also works as a kind of filter and actually draws some of these tiny particles down into it. As a result, black dirt begins to accumulate in lines, small patches, corners, and edges of carpet.
  2. Hard to Vacuum Areas
    It’s not uncommon for soil and dirt lines to appear frequently in spots of the carpet where it is difficult to properly access with a vacuum cleaner. The longer a particular section of carpet goes without adequate cleaning, the more likely it becomes that this area will develop filtration lines.
  3. High Traffic Areas
    In some cases, soil filtration lines begin to build up in areas that see the most foot traffic. If you have carpet adjacent to a commonly used door to the outside, this section of flooring will naturally be more exposed to dirt and, as a result, be more likely to produce filtration lines.
  4. Cigarettes and Candles
    • Burning candles can result in more soot being sent into the air. Smoke from cigarettes can also create air pollutants, leading to a much lower indoor air quality.
    • If you frequently smoke or burn candles in your home, this can lead to filtration lines emerging on your carpet.
  5. Closed Door(s)
    Doors that are left closed, especially for long periods of time (such as overnight) can ultimately create dark patches and lines of dirt in the carpet.
  6. Furnaces
    In some cases, a furnace that lacks a functioning filtration system for the air can add to this problem, resulting in a number of soil lines across the floor.
  7. Lighter Carpet Colors
    While this isn’t exactly a cause for filtration lines, it is a reason that they might catch your eye. Lighter colored carpets tend to show these black lines in a more noticeable way than darker colored carpets, for the obvious reason that dirt stands out more on a lighter background.

While plenty of things can cause soil filtration lines to appear at the edges of your carpet, the above list includes a large majority of the ones that you are more likely to experience at home.

Brushes, rubber gloves, and cleaning supplies to clean a home for the holidays

How to Clean Filtration Lines in Carpet

Now that we know the range of what causes filtration lines to build up in carpeting, let’s take a look at how to clean filtration lines in carpet.

Due to the nature of soil accretion in carpeting, it can actually be very difficult to remove the stains entirely using only at-home and over-the-counter cleaning products. That being said, here are the steps to follow if you want to try clearing out the filtration lines yourself.

NOTE: Before getting started, some experts recommend that you wear a mask to filter out debris and other particulate matter. This goes especially for anyone that suffers from respiratory issues.

  1. Vacuum the carpet, focusing on the most highly affected areas. This helps to clear away stray particles and other light surface materials, even if you aren’t able to get in the crevices of the carpet.
  2. Without water or cleaning spray, use a scrub brush (not a washcloth) to wipe at the edge of your carpet at the baseboards, where most filtration lines tend to occur.
  3. No two filtration lines are identical, so you may need to try a few different cleaners before you get it just right.
  4. Finally, use a wet/dry vacuum to finish up cleaning the areas to which you applied the carpet cleaning solution.

Once you’ve completed the above steps, you will probably notice a significant improvement in your carpet’s cleanliness and visual appeal.

How to Prevent Filtration Soiling in Carpets

After you’ve spent all that time scrubbing and cleaning, you’ll definitely want to protect your carpets from getting more filtration lines down the road.

The easiest way to do this is to make sure your ventilation system is always clean and clear. Make sure to have your air vents and ducts cleaned and to replace your air filter whenever necessary.

Soil filtration lines can often be linked back to dirty air vents or ducts or a dusty, old air filter. If you keep your central heating and air conditioning in great condition, you’re setting yourself (and your carpet!) up for success both now and into the future.

Call in the Carpet Pros

As we mentioned, you might not actually be able to get all the filtration lines out on your own. That’s what we’re here for!

If you need further assistance with getting filtration lines out of your carpet, get in touch with the professionals at Whitehall Carpet Cleaners. We use advanced techniques — such as hot water extraction — to provide the best possible cleaning solution in Columbia, South Carolina, and surrounding areas.

Call us at 803-732-3200 to schedule a cleaning today. We look forward to helping you restore your carpet to its cleanest and most beautiful look in years.