Poppy
what's the best size of plywood 9mm or 12mm? To panel the van that is
Depends where you're putting it and what you want to put on it, hang off it etc. I and and many others have gone for 12mm floor, 6mm side walls and 3mm for ceiling. Some have used 9mm for the floor but if you are insulating underneath then the wood supporting batons need to be closer together.
i forgot what van you have
As above. I used 6mm on the walls and 9mm on the floor. I spaced them at 400mm centres though and that was too far as there is a little too much flex.
right. i had a duck not long ago,a minibus. normally i'd use kingspan for the floor as its more or less rigid enough to walk on.another tip is put 2 battens across the van at about 150mm centres,,no insulation ,and use this to get services from one side of the van to the other