My roof has fiberglass on top then foam filled center and finally a thin 1/4-inch plyboard for the ceiling. My 2008 Starcraft 14RT Popup ceiling has three inches of foam in the center sections and maybe as little as two inches on both ends where the roof slopes down some...
I would go the route of using MOLLY ANCHOR BOLTs first from the ceiling side ... These spread out between the ceiling plyboard and the foam inside the roof... Once you install these anchors you can remove the screw and all stays in place on the ceiling...
We use these anchor bolts all the time on my other trailer that has hard walls to mount thing with...
Looks like this...
Pull down a ceiling light and see how much room you have between the ceiling and the roof. You may have to use a shorter screw in the anchor bolt.
No sense pulling a hole through the roof if you don't have too...
If this idea doesn't do good just to let you mount your thumb turn buttons maybe you can use the anchor bolts to hold up a small back board to the ceiling and then attach the turn buttons to that...
Putting round head bolts all the way through the roof would be my last option here. If i did have to resort to that I would use those four through the roof bolts to hold up a 1/2-inch back board on the ceiling side and mount my turn buttons to that... Once you paint up the back board it should blend right into your ceiling decor... In this case these back boards could be 1x4 wood strips where the turn buttons are required...
Not sure how your LATCHES are - A picture would be helpful.. Some of the earlier POPUP had straps installed to the ceiling to hold the door assy.
My door frame has small oblong holes in them to align up with four turn buttons like shown above... Plastic latches doesn't sound very strong to me to used for the heavy door assy...
You roof looks very similar to mine in some photos I was looking at on-line...
Just some my thoughts here...
Roy Ken
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
RETIRED DOAF/DON/DOD/CONTR RADIO TECH (42yrs)
K9PHT (Since 1957) 146.52M
2010 F150, 5.4,3:73 Gears,SCab
2008 Starcraft 14RT EU2000i GEN
2005 Flagstaff 8528RESS