What is this horrible noise in our new Class C?

Is the noise steady with a regular rhythm, or does it vary with a random pattern? A friend with a similar setup found by having a person or some other load up in the bunk, the noise diminished. The problem was some sort of adhesion between the cab roof and the cab-over bunk. I don't know how it got fixed other than a local RV repair guy waved his magic wand and all was good. I personally had a noise thing like this on a pop-up truck camper and the same repair guy went over it and found self-tapping screws that were not biting in real well.