No...there's no need. The options are there Ken, and different people will have a different take on it. Decide what you're hoping to achieve and spend as you see fit. Personally, I think a well insulated van is an investment....warmer in winter, cooler in summer...quieter all year round....if it cost you £200 and a couple of long weekends to achieve it, it's money well spent...
NO....it will sweat between the layers and you will have a pool of water collecting along the floor line in both winter and summer..trust me ken...I know what i'm talking about
i don't want to sound patronising, but can i suggest you read around the subject before paying for stuff that may or may not work depending how you install it, or taking decisions based on anecdotal advice...As i've said, people have used different materials (ranging from worthless to extortionate) to achieve specific things...if you want to insulate for heat use heat insulation products...if you want to reduce noise, use noise reduction products BUT you need to first understand the techniques employed to make them work effectively.
What works for us, but may not for all, is that after freezing our brass balls off (obviously not the wifes...) I insulated all the panels (including roof behind the headliner) I could get at with a closed cell foil faced foam. It wasn't bubble type but that was by accident rather than design. We carry JK foil window things & they work for keeping heat in, & out if you reverse the suckers. The most important thing was the vapour barrier behind the trim panels. I did it on a camp site over 2 days & the difference was that ice formed on the outside of the bus & not the inside. We keep the roof down in the cold. This was in upper NY state as the weather started to change & believe me it was cold. I will re-do the vapour barrier during the refit this winter. (& I've just bought a propex)! Hope that helps but it is only my experience.
if you want to do a proper job use Kingspan...for the floor, Kingspan for the roof, purpose made aluminium-faced closed-cell foam for the interior. Thermal window pads for the glass....a poprex to maintain temperature above dew point, and a ceiling fan or passive roof vent to encourage air flow OR/ lead flashing for stopping leaks in gutters, because it gases off volatile bituminous particulates , Mylar-faced bubble wrap because it's shiny and looks like the proper stuff, cheap carpet underlay because it retains moisture like a sponge, and rock wool because it's a lung irritant
