Camper_Jeff_&_Kelli wrote:
You can't just put a sheet of foam board in the bed of the truck. You need to have a solid material around the perimeter or the weight of the camper on the stiff, solid sides will crush the foam down and the flexible meddle flat area of the camper will not compress the foam as much as the hard edges. I built a wood frame for my TC and the inside of the frame has foam board. I think what you have there is the edges settling and the belly being pushed up in a bowing fashion.
Picture of mine.
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If that is the case why not just have a piece of plywood?