Drilling holes (for curtains) in the ceiling of the 1st floor(2nd floor in the US) of my house I ran into a steel rod in the middle, running parallel to the outer wall. The steel is about 2.5cm in and starts one meter from the side wall. So far, it's at least a meter long. (I drilled three holes and all three hit it.)
Is this a rod and how thick is it? Can I assume that I can drill a few centimeters to either side and not hit it?
(I'm assuming that I can't/shouldn't try drilling through it)
(This is in the Netherlands and the house is from 1985 if it matters)