Roof options for folding camper

I’m looking at a few options for how to build a roof of my folding wooden camper. There’s more information in the build forum. 


Options: see sketches
1. pmf or vinyl roof over cork and plywood
2. Painted plywood roof with cork adhered from bottom.
I’m leaning towards option one because I don’t want the cork to fall down. It just makes more sense to me to put the cork on top of the plywood. It will be a whole lot easier.
Thoughts?
The entire roof will be lifted by hand when I set up the camper, so it needs to be ultralightweight.
I want to keep the roof under 60 pounds
Options: see sketches
1. pmf or vinyl roof over cork and plywood
2. Painted plywood roof with cork adhered from bottom.
I’m leaning towards option one because I don’t want the cork to fall down. It just makes more sense to me to put the cork on top of the plywood. It will be a whole lot easier.
Thoughts?
The entire roof will be lifted by hand when I set up the camper, so it needs to be ultralightweight.
I want to keep the roof under 60 pounds