After weeks of googling it turns out there is no definitive “this is how you insulate your van, for winter use and to stop it rotting” answer..

This is my plan for my lovely new (to me) Transit…

35mm thick white dacron/polyester stuck to panels with high temp. adhesive (doubled up where space allows). Then I’m going to tape continuous sheets of foil covered bubble wrap over the top, this should also act as a vapour barrier.

I’m not convinced that glueing the bubble wrap straight to the metal would be as effective, as I’ve heard it needs an air gap to work properly?

What I need is someone to tell to stop worrying about it all and just get on with it! 😉

I used a combination of thing on my last van, including conventional loft insulation………after a few years it failed it’s MOT due to rot…

Have you checked the VW T5 forum lots of info there.

The insulation value of bubble wrap is minimal but it’s use over the top and tape all the joints with silver foil tape would work as a good vapour bar.

I live on that forum! A lot of people just seem to use one layer of bubble wrap, I don’t reckon that’ll be good enough in the Cairgorms this winter!

i spent a long time pondering this too, when i did my van. in the end i decided no matter what i did condensation was gonna form at some point on the inner metal surface so better plan to deal with it. i wax oiled the bottom of the cavity, making sure to keep the drain holes clear and then packed it out with this stuff;
http://www.rockwool.co.uk/products/u/2011.product/9901/building-insulation/rainscreen-duo-slab%C2%AE
the outer surface is compressed so that water cannot penetrate. van was cosy. i did it in 2004 and owned in till earlier this year without any problems.

lots more info here

I lived in mine for one winter and was plenty warm

I followed damions lead on this and it seems to have worked out very well.

For the roof, I stuck on two thicknesses of closed cell matting (cheap from Go Outdoors) and over that I managed to source a genuine roof lining from a minibus variant of the Trafic.

I’ve slept in it on numerous occasions and found it to be very warm. Noise levels are excellent too.

Sheepswool insulation. Not rotting, handles moisture really well.

Got it in my T5 from Amdro.

forget the vapour barrier it will never seal airborne moisture out, but will succed in trapping the moisture that condenses out onto the metal, your insulated and sealed area will be very damp.
it needs to breath.
spray wwaxoi or similar in lower 6inch of all panels before you put any insulation in.
any fibourous material can become sodden fibreglass/sheepswool/recyc l e plastic all the same if sat in water.
ive used solid insulation board for lower few inches and all wet areas like inside doors, then sheepswool above.
ply line and carpet, job done.
if fitting a fridge and wanting flush to units t4 or t5 normally need foil bubblewrap insulation and no ply line to recess fridge sufficiently.

I like the idea the idea of “kingspan” at the bottom of the panels! A lot of people use sheepswool….hmmm