Home / Forums / Campervan Conversions / Insulation materials
Insulation materials
Hi, I recently bought a fab Fiat Doblo Cargo small van to use as a second vehicle and camper. Now with Autumn coming I need to sort the insulation and carpeting.
I've had a few views on insulation and am not sure what to follow.
1) 12mm insulation as sold by Rainbow Conversions, Cambs
2) Therma Wrap (4mm foil sheeting with a kind of bubblewrap centre to separate two foil sheets) - this claims to give the thermal qualities of 65mm polystyrene, enhanced with carpet on top.
3) Household stuff thats probably too thick for my van
From my pics you will see that there's a lower half with a space between panels (trim removed to show the cavity) and a higher single skin area. I need to insulate both these spaces, and perhaps do more on the ceiling.
Lower area) There is ample room for thick insulation, with some pushing and shoving I'm sure it would go in! Then I could ply the front of the metal and carpet that - any thoughts?? And how thick should this be - I have some 5mm stuff that was in it when purchased?
Higher area) This again seems rather uneven and therefore tricky, perhaps even a job for a professional. I could put ply right across it but would lose the 5cm recesses (where windows could be on some models), so am uncertain about that - of course this could be a space for thicker insulation, with the foil and carpet stuck on the ply. Thoughts again much appreciated.
Ceiling) I've done the ceiling with the Therma Wrap, finished with the ceiling trim taken from a Doblo car. This should be quite good protection? There is space between these (between the beams) where I could put further insulation - is that worthwhile?
Floor) There's also the floor to consider - the original 12mm ply is down with a rug on top at the moment. I dont want to raise this really as I want to keep the space - would ply + carpet be ok (the foil stuff wouldnt work there I guess)?
Many thanks, geoff
Hi Geoff, Just to add a bit to what Darren has already said; I had a natter with a rep from the folk that make the foil bubble wrap, AirTec in my case, and he said that to get the most out of the insulation it needed an air-gap between the cold outer surface and the foil. I decided that a layer of thin carpet would probably be a good middle ground - an actual air-gap poses all sorts of problems in suspending the insulation sheet.
I did insulate the floor - my Relay has a corrugated floor, so I put battens on the upper ridges, then the insulation with the floor boards on top. I have enough roof height that the loss of about an inch wasn't a problem.
Interestingly, today was red hot and my van, parked in full sun, stayed cool until past mid-day - so its working.
Thanks guys, your comments defo help me proceed with a few less nerves in my belly!
The air gap issue seems interesting - I dont have spare carpet at the moment, maybe a double layer of the foil wrap would do it??
thanks again, geoff
Hi thanks again for comments made so far.
After reviewing feedback and talking to a few people yesterday I'm considering changing my approach a little.
Loft insulation material in the lower cavities – it has been suggested that I fill this loosely so that there's some air still in the cavity, as it was thought this would improve insulation. Do you agree with this?
And I'm also wondering about venting of the cavity – I guess that moisture will arise, even just from the metal getting hot in the sun and then cooling at night and this needs to be able to evap. If I tape or ply over all the areas where venting would previously have happened into the van, leaving only whatever air flow happens underneath it, will that be sufficient so avoid a build-up of damp and therefore possible mould / smells?
Ply on high areas: mounting this is tricky and I wonder limited benefit? Instead I could put several layers of the foil to level out the unevenness in the Window cavities and then carpet over this, all held with trimfix temperature resistant spray glue. Seem ok?
Filler around lower ply - some of this I will screw on with carpet already glued to it, so that it could be removed to access electrics if that was ever necessary. However I may fix other pieces permanently – someone suggested using decorators caulk for this so that I can glue to it (rather than silicone stuff which may be more difficult in that way). Would you suggest sticking with the silicone stuff as its only going to be small areas? – what I've found says indoor use only, so damp could be an issue.
Thanks again for looking at these further questions – I really want to get this right without unnecessary work. It really is a fab van and a fun project!
Cheers, Geoff
Loft insulation works well. However, do not use the traditional type made of the itchy material. This insulation is not to be used in habituated areas, as the fibres are not nice. Instead use a similar material that is made of recycled plastic bottles. It looks similar and works in the same way, but is much nicer to the body. I bought mine from B&Q, about £7 per roll.
As long as there is some space for venting you should be OK.
If you wont ply the sunk areas, when you lean on them it might feel unfinished or cheap. Ply lining definitely gives a finished feel to the walls.
I would recommend screwing all ply panels to the walls. Caulk isn't an adhesive, and wont stick well. You could use Sikaflex or a similar product as these are adhesives, and are very strong. Screwing is much easier though.
You can glue the carpet to the panels, leaving the corners unstuck. Then screw the panel to the walls with the screws passing through the corners you havent stuck. Then once screwed in, stick the carpet corners down. The screws are then hidden.
Cheers
Camper Van Life is brought to you by Darren Lambert, a big fan of camper vans.
Hi Geoff
All of the insulation types you have mentioned are good.
The Therma Wrap is the easiest to use, as it's so pliable.
Lower area) I would use the thickest insulation you can, to ensure it works at it's best. Although you could use Therma Wrap throughout the van, including this area.
Higher area) Therma Wrap seems the best option here, as it's easy to fill the spaces. Most people ply line over the top of the recesses, a there is little you can do with them. Although you could insulate and ply inside the recesses, and then use the recess for storing things if you make a panel or net to go over the top.
Ceiling) What you've done sounds like a good solution. The factory lining you have put it would fit really well and therefore it will insulate well.
Floor) Many people don't insulate the floor area. It's the area of least heat loss. Any sort of insulation will reduce head height. The 12mm ply will act as a good insulating barrier. With the rug on top, or perhaps a more fitted carpet later you should have good insulation there.
Cheers
Darren