Our camper van has a penthouse top which raises to give a full 7’2″ of standing room. It also leaves a long opening in the roof of the van that has a steel reinforcing ridge. This ridge makes a perfect place to put a bed at night, but first we had to build one. The dimensions of the hole in the van roof are 37.5″ by 9’8″ long. The bed must overlap up to 40″ wide to sit on the ridge. Of course, we don’t want the bed to take up the whole length of the hole or we won’t be able to climb up. 9’8″ is 116″, so a 81″ long bed (6’9″) would leave 35″ (almost a yard) to climb up and down in.
After calculating the load bearing capacity and, more importantly, the cost per square inch of Aluminum, Titanium, and Carbon Fiber, we decided to use 3/4 inch plywood covered by a foam upholstery cloth as our load bearing panels. We wrapped the plywood with the foam, stapled it down, and then stapled the other end on top, after folding the edges over. (We also used 3M 77 spray adhesive to prevent it from dropping away from the center of the board.)
Three 40″ by 27″ panels give us an 81″ long bed. The panels stow in the steel ridge below the top when it is lowered (part of the top leaves enough room for two of them to stack). Although they reduce the headroom in the rear of the van by a few inches, we don’t really need it when the top is lowered. When we make camp and raise the top we simply prop the panels upright at the front of the van. When it’s time to go to bed, we lower the panels back down into the steel ridge, cover them with bedding, and climb up into the penthouse.
We also made a bed similar to yours. We only use it when we take the grandkids with us. We made ours in 3 pieces…one piece is 16 in and we leave it in all the time as it makes a nice shelf for storing stuff while traveling.
Anne