Stair Tread Carpet Stain
Is not uncommon to see stains on the carpeting, throughout your home. Some of these stains can be difficult to remove while others can be removed with soap and water.
High traffic areas within your home, such as hallways
and staircases can be targets for carpet stains. Since these areas are
walked on more frequently, the risk for carpet damage will increase.
If you pay special attention to the front edge of the stair tread, you will notice a thin strip of dirt. This type of carpet stain is common and usually located towards the center of the stair tread.
This section of the stairway carpeting is used the most while walking up and down the stairway. If your shoes or feet are dirty, it won't be long before your carpeting has stains like this.
Take a look at the carpeting color, it's light brown or beige. The stains are darker and almost black in color, not the color of dirt. These stains were probably from someone who worked on cars, either in their garage or as a career.
These stains could be from something else, this is just an observation.
Home Repair Tip: It's not a bad idea to remove your shoes as you enter the home. I have worked on homes where the carpeting is over 25 years old and in reasonably good shape, because the homeowners remove their shoes as they entered their house.
I started doing this a few years ago and it wasn't that hard of a habit to get into.