Sleeping Platform Building Material

[adrenaline503]

Hello all,

I am anticipating building a sleeping platform in the back of the Nissan in the next few months and am looking at some options.

I have seen most people build them out of plywood of various thicknesses. Ideally something lighter would be ideal, as well as water resistant. Is there some sort of high density foam that could be used? I do plan on carpeting if that matters.

In addition to the drawers at the tailgate, I also plan on using boat hatches up forward to access smaller items.

Thanks for the help...

 

[Ridgewalker]

Just a few thoughts here.

Plywood (marine or exterior) is pretty good/strong/economical stuff to build with. You can always lighten it by cutting holes in it...skeletonize it. Also weight wise you can box in to stiffen/strengthen areas without adding a lot of weight.

Carpet is heavy and of no structural value. If you need padding, try closed cell foam...light, cheap, but not real resilient.

Also you could Herculine the plywood to help waterproof it.

Plastic for structure is not really very strong except structural foam (it has tiny bubbles for structure between the somewhat smooth surfaces). It is costly...toxic when burning...and difficult to assemble well.

These are just from my experiences, so take them with a grain of salt. Us old guys need you younger ones to come up with new ideas. So if you have an idea...try it. It may be time well spent.

 

[Topher Walters]

I have built several platforms in truck beds for different reasons. Sleeping platforms and work/tool platforms. For me it was easy to use exterior grade plywood and then just primer it with a good primer paint. With a good paint on the plywood it will do fine with water. I used exterior grade plywood and a good primer for some side racks on a utility trailer I have and they are just fine after 5 years outside. I like the idea of trimming weight by drilling out some of the wood that you wouldn't need.

 

[SOAZ]

Try something new!
I used plywood and then covered it in two layers of carpet padding. (whatever its called, the stuff you put under carpet) then I put the really cheapo thin, but strong indoor outdoor waterproof carpet over it.
Its all so heavy. I someone can show a better way I will do it! I'm actually thinking about getting larger springs in the rear because its so heavy once I'm loaded down for a trip that the rear sags.

 

[jayshapiro]

alternatives

When we built the sleeping platform in my Land cruiser we just used treated plywood and then put a foam mattress on top and custom built some very handy shelves / cabinets on one side with bungy cargo nets to hold evrything in. It worked very well, but I agree with your point about it being heavy.

If we were to do it again I'd look at one of the following alternatives:

Nidacore - very strong/light composite used in Earthroamer.

www.alcancomposites.com - they have some interesting structural foam sheets that are moisture/rot proof and lighter than plywood

Tricell (I think that's the right name) an interesting sandwich material with little triangle shaped cardboard spacers between two faces. VERY light, and quite strong if supported correctly.

good luck!
Jay.

 

[paulj]

I used 5 1x3 boards to span 4' wide interior of my Element. On top of these I put 2x4' 1/2 plywood boards (good quality birch). This was lighter than 3/4" plywood. Also it is easier to assemble the structure with the smaller boards, and then attach the plywood on top of that.

I painted the plywood with polyurethane, and covered the long edges with aluminum channel.

Over the whole thing I have place 2x2 interlocking foam panels (sold for flooring). The foam is loose.

The structure is held together with 1/4" hardware. The plywood is attached with pancake head furniture bolts (6mm hex driver hole). These bolts have a very low profile head. An alternative is to counter sink the holes, and use hex head bolts.

paulj

 

[articulate]

FYI, the exterior plywood to use is called OSB - it's often used for making signs that sit outside. It's inexpensive, and the adhesive used to hold it all together is a resin, so it's going to hold moisture at bay very well.

CDX, another type of sheet good, would be okay if you waterproof it somehow - epoxy resin, herculiner, primer, or something along those lines. But it's light and strong. You don't really need something like a quality birch plywood because that's not necessarily going to mean it can hold up to the elements (no pun intended, Paul, but it was handy). When they say "Birch Plywood" that indicates the veneer face, which is only the outside layer. It's not the core nor the adhesive used in the core. You could spend $90 per 4x8 sheet of birch ply, and it'll still get killed by weather.

Cheers,
Mark

 

[paulj]

In my case the plywood does not need to be particularly weather resistant. I chose the birch as much because it has a smooth finish (no splintering knot holes), and I could buy a couple of precut 2x4 pieces for a reasonable price from the hardware store.

Initially I intended leave the painted plywood uncovered, but decided that the foam mats gave a more pleasing surface - both for cargo when on the road, and sleeping.

In retrospect I could have used carpet on cheaper panels, but then I would have had to come up with a different method of attaching the panels.

On earlier projects I weatherproofed plywood by paint it with epoxy, the sort of stuff that is used for stitch-and-glue boat projects. In one case I sprinkled the epoxy with salt, which I later washed off, leaving a coarse texture (this was for a tailgate liner).

paulj

 

[nvprospector]

If you want to go with a different material that is light and strong I would recommend PolyMax Boards. They are a high-density polyethylene sheet that is more durable than wood. Matter of fact when you work with the boards you work with it just as you would with wood. It does cost a little more, but it does not have to be treated and its weight is lower and strength is higher than apiece of plywood of the same size and thickness. I am building an off-road teardrop trailer using PolyMax for everything above the frame and it is very light material.

http://www.teksupply.com/farm/supplies/prod1;ts1_building_materials-ts1_plymax_plastic_wallboard;pg106835.html

 

[frgtwn]

MDO or OSB?

Mark, maybe you are thinking of MDO, medium density overlay, which is used for signs. It has a smooth fiber coating on front and back and is pretty nearly weather proof, even unfinished. The edges will need to be treated for a severe use application- the inner material is exterior plywood.

OSB, oriented strand board is used for decking; roofs and sometimes walls. There are even new words in the building vocabulary to describe problems associated with the swelling of the edges under a composition roof, due to moisture.

I would not want OSB anywhere near my vehicle. I did build a desk out of it once for an architect. He liked it. I'm just glad the check was good.

I built a 16'x12' playground backboard of MDO, which saw 2 years of unpainted use (It was fine.), and then 4 more years painted on one side. When I took it down all 6 sheets were good enough to reuse, if one didn't mind the screw holes.

Weight tool: generally 4x8 ply (and OSB) weighs 25 LBS per 1/4". So, 1/2" will weigh about 50 pounds.

I would be looking for something besides wood products for a vehicle platform.

Perhaps I"d go to the trouble of a torsion box with some kind of matrix inner core.


Dale

 

[paulj]

Some Element owners have made a sleeping platform from plastic plumbing pipe. They don't use any top boards, using instead an airmattress than is stiff enough to rest on supports spaced every 15" or so.
paulj

 

[HMR]

Keep it simple...

I just used regular old plywood for the deck:

I spraypainted everything with primer. The top surface is covered with thin rubber material I glued to the wood. I used some aluminum edging for the rear end:

All materials were purchased at Home Depot and the entire build could be done in a long afternoon. The platform gets soaked in saltwater just about every day from my swim-happy dog. When it gets dirty, I take it out and hose it off. I can carry the whole thing easily. It also holds several hundred pounds without flinching. Before I got a RTT, I just threw an inflatable (Twin Bed size fits perfectly) mattress over the top. After >1 year of abuse it still looks new.

 

[Clay]

If you want to go with a different material that is light and strong I would recommend PolyMax Boards. They are a high-density polyethylene sheet that is more durable than wood. Matter of fact when you work with the boards you work with it just as you would with wood. It does cost a little more, but it does not have to be treated and its weight is lower and strength is higher than apiece of plywood of the same size and thickness. I am building an off-road teardrop trailer using PolyMax for everything above the frame and it is very light material.

http://www.teksupply.com/farm/supplies/prod1;ts1_building_materials-ts1_plymax_plastic_wallboard;pg106835.html

That stuff is pretty cool. Will the company in the link send just one or two pieces? Can Home Depot or anyone special order it?

 

[nvprospector]

That stuff is pretty cool. Will the company in the link send just one or two pieces? Can Home Depot or anyone special order it?

Yes, they will send one or two pieces. I tried Home Depot and Ace and they said they never even heard of it. I tried getting it through the manufacture and they want you to order a semi truck load. Teksupply is the cheapest I have found the stuff so far and they can do custom sizes if you are will to get a lot of it.

 

[Ridgewalker]

PolyMax board...pretty interesting. The main issue I see is a standard 1/2"x4'x8' sheet is 73 lbs! A lot more than 1/2" CDX.
Maybe just using the 1/16" to cover the plywood would be OK, but to build out of it sounds pretty heavy.