Steel stud stains

Q: Despite an excellent heating and ventilation system, I have to clean stains from the interior walls of my house every two years. The stains appear wherever wall studs exist and these outlines can only be removed using a very strong cleaner and lots of elbow grease. The house is totally framed in steel, and it's been suggested that the problem is dust, attracted to the steel by magnetism or some sort of static electric charge. What do you think and what solution can you offer?

A: I doubt that magnetism or a static charge is the cause, because neither of these could hold dust as firmly as you describe. Perhaps the cause is cold weather condensation. If the steel studs go from near the outside surface of the wall to just under the drywall, then they could be creating cold spots on interior walls by conduction. Do the stains seem to build up faster in winter? That's when condensation would appear, as warm indoor air hits the cold strips on the walls. Not that this is much help, because adding an unbroken layer of insulation to walls isn't easy nor convenient. Does your home have a heat recovery ventilator? This is one appliance that reduces indoor air humidity enough to stop this sort of condensation in some cases. Is your home fairly new? Have you sought the advice of the builder? It's important to raise your concerns in this way. Since they've probably had more than one complaint of this sort, they may have identified an excellent fix.