Sleeping platform design feedback?

Hi all... I'm new.

I will be road tripping in September and have been researching sleeping platform designs. I'd sure appreciate your input as I am not a carpenter by trade!

The rough drawing attached shows my own one-person, cot-sized design drawing (I would use a cot, but I can't find a frame short enough. And I'd rather it was strong enough to support some cargo).

It must be sturdy/stable, comfortable, easy and lightweight enough for one person to install and remove, and it would be great if it could store flat in the garage when not in use. The basic plan uses a 72" x 30" footprint, which will fit a comfy roll-up futon cot mattress. The plywood top is supported by rails, one "broken" to all for wheel well clearance. The rails bolt into the top, so I can remove them for storage. I will also add closed cell foam cushioning and a fleece or carpet covering. I need 9" of clearance below for storage bins (factored into design).

1. Any concerns about the design?
2. Could I make the rails out of 2 x 10 cut-to-length boards instead of building them from 2 x 4s?
3. What is the thinnest plywood you think I can get away with? I want light weight but don't want to sacrifice strength/stability.

Many thanks!

 

Have you considered engineered I-joists, like these? They will save you quite a bit of weight over 2x10s or built-up 2x4s, and are at least as strong. You can make them yourself with a table saw if you have access to one.

Also, do you have a beam centered beneath the platform? If not, you'll have to use quite heavy plywood, at least 3/4". I would add a central beam, and either lateral bracing or bridge blocking to stiffen the platform from side to side.

 

Check out this thread. I oirignally planned to do what you are planning but i think this is a much lighter, faster and easier to remove/store option!

http://www.tacomaworld.com/forum/1st-gen-tacomas/308557-sleeping-platform-dog.html

 

Thanks for the input! The I-beams look like an interesting possibility. I would consider the bedframe idea, but I have been unable to find one short enough for the bed of the truck. I have 72" MAX, which will allow me to just close the tailgate, I think.

I'm liking this set-up a lot: http://www.christopherwking.com/projects/luxury-truck-bed-camper-build/

His design uses 2x2s instead of 2x4s, which would save a lot of weight as long as I can build it with plywood only on the top. It also incorporates a cross-brace as you suggested I add. I figure I can add some corner fittings to the underside of the plywood on the top so it sets snugly into the frame, so it won't slide around. Then I can remove the top separately, which will make it easier to move. The frame would be light enough to hang in my garage.

It's fun to plan a trip!

 

That is a pretty nice set up there! I like the opening between the beds. I lived out of my truck for a couple months when I moved to AK back in 2007 and had a flat platform with plywood and then just put rubbermaid bins, the kind designed for under your bed, underneath the platform. Worked great.