What Is That Dark Line On The Outside Edge Of My Carpets?

Filtration Soiling

Safe Nontoxic Carpet Cleaning

Filtration soiling is the next article topic from NewAge Natural and Organic Carpet and Upholstery Cleaning.

What is filtration soiling? For the 29 years I have been in business, I have seen this condition in most homes that have carpeting.  Filtration soiling is the grey & black line that borders rooms, hallways, and stairs. It’s about 1/2 inches wide and looks like this.


It is caused by a gap between the wall and the floor, and is a small space anywhere from ¼ to ¾ of an inch in width. Over the past 29 years, I have cleaned in new construction and remodeled homes, and have talked to contractors about filling the gap with caulking or silicone.  What happens is as the house breathes, air travels through the gap and the carpet acts like an air filter.  Soot, dust, contaminates, and other airborne microbes get caught in the carpet and it looks like the picture I’m including in this article.

This picture shows the tacks used to install the carpet that puncture the backing and air travels through the small puncture holes and the filtration soiling occurs even in this small area. The arrow points to the small black dots at the base of the riser.

This filtration soiling does not become visible for a year or longer, which at that point my clients think it’s from poor vacuum cleaning.  It has also been mistaken for mold.  There really is no way of preventing this from happening after the carpet has been installed, but it can be prevented prior to installation.  If you have made the decision to install new carpeting, simply pull the carpet back and run a bead of caulking or silicon along that gap between the wall and floor and this should stop the air flow.  A simple DIY project!! If it’s a new build or remodel, seal up the gap before the new carpet is installed. Do not count on the contractor to do this!

This final picture shows a great example of the area along the stairs where there is no gap and the filtration stops. If you have any questions, please contact me directly by email or phone.