I have been in several homes lately where the homeowner has complained about the black lines around their baseboards and under the doors.  First, don’t think you are a bad house keeper, you have very little control over this happening.  Second, call me and I will help determine what is causing the problem and potentially help you solve the problem.

There are several reasons why this happens but lets start with the what it actually is.  The black lines are caused by very fine particulate soils traveling  through your carpet fibers, usually next to a wall, and being trapped there.  Over time this soil will build up and cause the black lines.  This fine particulate soil can come from a multiple sources, for example, if you burn candles the soot residue will eventually fall and can cause the lines around walls, furniture, draperies, ect.  The picture below is an example of soot from burning candles settling around where a chest sat.  This is the easiest filtration soiling problems to correct.



Another reason you have these lines is because the air moving through your home is being forced through the walls due to poorly designed HVAC systems. No matter how often you vacuum and change the air filters these lines will build up.  Of course, vacuuming and changing the air filter will slow the process.  Below is an example of filtration soiling along baseboards.

This is the most difficult filtration soiling to remove because the air travels through the fibers and even into the backing of the carpet. It also difficult to remove due to it being so close to the baseboards, this type of soil requires much agitation to be remove and agitating that close the the baseboards can cause damage to the baseboards.

Here is an example of it under a doorway.

This type of soiling under the doorway can be much easier to remove because agitation is not a problem. However, if this problem is ignored and not cleaned regularly it may also become permanent.


  1. Hire a quality HVAC company to correct the airflow problems.
  2. Vacuum regularly including using an edge tool to get in the crevices.
  3. Change air filters often.
  4. Clean your carpet often, if you allow these lines to sit for long periods of time it will be hard, if not impossible, to remove.
  5. If you are changing carpet, choose a darker color (even if you do the 1st 4 you will continue to have the problem only at a much slower pace).

I hope this sheds some light on problems you might be having.  Till next time.