I don’t know if Monaco change the way they made the roofs but on my coach I used one and a half inch self tapping screws, and Daycor to seal the mounting points of my solar panels. Four panels have been up there for seven years and the other four on one year and I have been driving 60 miles an hour in some very wicked winds Without any problems. Four of my panels are set up to tilt so they are mounted with aluminum angle iron with four screws at each end. The other four stay flat, but they end up being mounted with the same number of screws. Like I said, no issues . I have speakers in the ceiling, and if you drop them down, you can see into the cavity that the air conditioning ducking runs through in between the roof and the ceiling and my screws peek through about a quarter inch.