How do I get rid of the black lines around the edge of my carpet?

Where did those lines come from?

This is so common in homes in this area that when someone tells me they have gray or black lines at the edges of their carpet, I am 99% sure that  they are from filtration soiling.   When it’s not, it turns out that someone has been burning candles in a room with carpet (don’t do that!).  Filtration soiling is micro soiling over time as airborne particles are deposited on the carpet.  This is at the points of greatest airflow, and it is often caused by a heating and air conditioning system that is not drawing air efficiently.  Because it can’t pull as much air as it needs through the filters, it pulls wherever it can, and that usually means it’s pulling air through the crack between the wall and the floor, and pulling it right over the carpet, gradually building up a visible stain.

Can you clean it?

We usually can make considerable improvement in it.  The longer it has been accumulating, the harder it will be.  We will clean a three-foot section for you, which will do two things:

  • It will show you what results to expect for the rest of the carpet.
  • It will show us how difficult it will be to clean it.

We will quote the rest of the areas based on the portion we just did.  It usually runs between $10-$20 per area, an area being a room of up to 250 square feet, or hallway, or stairs.

Can I clean it?

Maybe, but probably not.  We use a very high-pH cleaner to remove this, so it’s important that we be able to remove and neutralize it.  If you did the same thing, using a strong cleaner like ammonia, you may get good results, but the carpet would remain at a very high pH and the resoiling would happen much more quickly than it happened the first time.

How can I avoid this problem?

Change the filters frequently in your HVAC system.  Unless your system is specifically made for HEPA filters, I recommend using the cheap, blue ones–they are cheap enough that you can keep a good supply of them, and change between every month and every quarter, depending on how fast they accumulate dust.  More expensive filters are more restrictive, so even if you change those frequently, your system will still have trouble pulling air through them, and you will wind up with more black lines on the carpet.