In out previous popup I installed 2 handles to attach 2 separate hanging fabric shelves for clothing. From what I can remember I used 1 1/4" long screws. Can I do the same on my 2015 Jayco 1007 UD?
Are you running screws into cross members in the roof or are you just screwing them into the ceiling panel? If the latter, 3/4" screws would be long enough and you'd avoid any danger of drilling through the outer skin. Alternatively, you can drill a 1/4" hole through the ceiling and use #6 or #8 plastic EZ anchors. Just snip the plastic drill tips off of the anchors and use shorter screws.
I want to get the hang shelves as close to the corners of the ceiling as possible. The Palomino I had had wood paneling behind the ceiling panel and allowed screws to go anywhere. Just wondering how the Jayco I have now is built.
If your popup has a roof vent, just check the thickness along one of the sides of the vent. I think most are in the 1" thickness so 3/4 would be my suggested max. Just try to get a more accurate thickness if you can before drilling/screwing into the roof.