New Hybrid Foamie Esterel/Gobur Type Design Brainstorming

[stcyrwm]

Hi All,

I have an old pop up camper that I turned into a gypsy style trailer that I need to redesign to be able to tow with a smaller 4 cylinder vehicle. I have removed the top part and so I am currently working with an already built out pop up trailer base with the original side walls about 16 inches tall.

The current plan is to build a foamie style top that is raised by the pop up lift system with foamie walls that fold up afterwards.

The walls seem relatively straightforward constructionwise because they don't need to carry any weight. I did have a question about whether people use PMF on the inside also, as I am watching every pound that I can and PMF over styrofoam seems about as light as it comes? Open to other ultra lightweight suggestions also.

The roof is more of a foamie challenge of because the trailer is 11' long and 6' 8" wide. I am currently thinking I would do a relatively lightweight box perimeter. I would start with two 11' long 2"x2" wood "beams" on top of the 4 pop up camper lift posts. And then attach 1/2" plywood across the front and back with an arch the shape I want the roof to be. Then run 1x6 wood or pvc boards lengthwise along the sides. And then add some 1/2 inch plywood cross members every two feet? I hope that makes sense. I am open to suggestions about this framework also?

My biggest question then is how to attach the foam to this structure? Or does the PMF do most of the work in that regard? In other words could I glue the foam to the frame and then just add the PMF - wrapping to the inrerio of the wood perimeter and that would hold it all together???

I did read through TinkerTailer's Folding Casita Thread (see: https://www.tnttt.com/viewtopic.php?f=55&t=72774&start=135) but this is a little different design

Thanks for any thoughts!
Bill