what thickness ply would you need for a single bed

Loris,
Caravans use 5mm ply but it is usually well supported all ways, but even then it bends a fair bit as the framing used is only 25mmx25mm pine.

IMHO The absolute minimum thickness would be 12mm, but only if there are a good number of supporting frames under it both ways, (length and width).

16mm would be better but would still need supports underneath (1 at each end and a couple evenly spaced between).

19mm would only need support along each side but is fairly heavy to handle in large pieces.

Disco

Good quality plywood in 10mm should be fine.

Loris, have a look at my Profile and you will see the bed i have in the back of my 79 Series. I put storage bins under it. It is very strong and does not move.

In the Troopy I sleep on top of the drawers.

I use 16mm MDF. It is as strong as.

Loris,

We used 12mm chipboard, supported only on the sidewalls, 3 panels running full width (1500mm) and about 650mm wide, with 25x40x3 aluminium angle reinforcing the long edges. The front and rear panels are hinged to the centre one so can be raised to access the gear below. This is adequate (just). I'd use 12mm ply with the same aluminium "next time". See our rig photos.

HTH

John

loris,
since 1997 I have used a bed made from ½ inch chipboard.
It was built by a cabinet maker in Melbourne and is still in perfect condition.
He cut heaps of 2 inch holes in the surface of the bed board to allow the foam mattress to 'breathe' and much larger 'gaps' from the sides to eliminate weight.
I put 7 plastic storage crates underneath the 'bed' which contain everything from food and cooking equipment to clothes and dive equipment with access from the back and front/side.

Mainey . . .

I'd suggest 12mm ply and supported at least every 600mm.
I make a lot of stuff out of 9mm or less, and don't believe it will support a body easily.

Gday,
How far does it need to span?

The less supports the thicker the ply.
The thicker the ply the less supports you will need.

My hard top camper has L400X W900mm spaced steel framework supporting 10mm plywood for a queen size mattress.

Hi Loris.

We have used 16 ml marine ply for the bed in our roscos trade mate camper.Has a slight lean on one side where there is no support for 30 mm.My advice is to go for 18 mm if cost is no problem.

Cheers Graeme.