Do You Have Ghost Marks?

Ghost marks. It’s not scary, it’s science.

Recently I was called by a contractor friend to come over and “look at something really weird.” When I walked in I noticed that dark lines appeared where framing members were in contact with the drywall. When he asked me what it was, I had to say, “that's scary” and that I had no idea. 

I went home and did some research. The house was built in 1995. It has steel framing which was popular at the time in Las Vegas because of the uncertainty of lumber prices. 

The lines are referred to as "ghost marks".  Seriously. They are caused by the difference in temperature between the drywall in contact with the steel framing, which is lower in winter and the drywall in contact with the insulation. The colder drywall attracts dust quicker than the warmer portions of the drywall thus creating the lines seen in many rooms. The difference in temperature is more apparent in the winter time than the summer time. Albert Einstein explained the mechanics of that problem decades ago, and the most understandable and simple translation of his equations would more or less sound like this. “Particles of dust floating in the air stick more to cold than warm surfaces.” Mystery solved. Way to go Mr. Einstein!