I want to add insulation to the ceiling, walls, and floor of my van as a first step to convert it.

What are the recommended/available materials for that aim?

By "convert" I mean to turn a regular vehicle into a something one can live in. Like this sweet Mercedes Sprinter below :)

Mercedes Sprinter converted

2 Answers 2


Answering my own question as I did quite a lot of online research on that topic.

I did this across different languages (English, French & German) which was interesting: habits/technics seem to vary from one country to another.

Criterias & vocabulary


  • Thermal insulation: must be excellent
  • Resistance to humidity: must be excellent
  • Compression potential: your vehicle vibrates a lot, over time the insulating material might get very compressed (i.e. rockwool). So you might want to avoid materials that compress a lot, at least for the walls.
  • Sound insulation: a great plus

Insulation-related scientific terms

  • Thermal Conductivity: the lower the value, the better
  • Thermal Resistance: the higher the value, the better
  • Specific Heat Capacity: the higher the value, the better
  • Thermal Diffusivity: the lower the value, the better

Eco-friendliness values:

  • Embodied Carbon & EPDs: carbon associated with making the material, read more

Insulating materials list

Cork sprayed

Cork sprayed insulation

Thermal conductivity at 0 °C: around 0.043W/(m K)

Price: in France, suber-spray.com sells a bucket of 12Kg for 215€ which can cover around 6 square meters if applying 2 layers (recommended). So a cost of 36€ per square meter if applying 2 layers (without adding the cost of renting/buying the gear to apply it).


  • can reach any tiny part, great to avoid thermal bridges
  • fast to apply
  • apply the thickness you want by doing as many layers as you need
  • cork has many eco-friendly features, from production to destruction (recycling)
  • good sound insulation
  • can be the colour you like


  • usually more expensive than other insulating materials
  • need of gear to apply it: spray gun, compressor, drill with mixer

Example of usage on vans: suber-spray.com/spip.php?rubrique10

Tip: it's expensive, so you might want to use a cheaper isolating material for the flat parts to be isolated, and this for the smaller hard-to-reach/hard-to-insulate parts.

Note: This insulating material is often use in sailing boats.

Buy sprayed cork:

Cork rolls/sheets

Cork rolls insulation

Cork rolls insulation applied in van

Thermal conductivity at 0 °C: around 0.043W/(m K)

Exists in different thicknesses, but the ticker the less flexible.

Price: 2 mm thickness, 150 x 50 cm = 10€



Reimo X Trem isolator

Reimo X Trem isolator

Reimo X Trem isolator applied in van

Thermal conductivity: 0,020 - 0,034 W/mK (maybe around 0.03 at 0°C?).

Made of expanded polyethylene.

Sold as roll.

A product of Reimo, a German shop specialized in converted vehicles.

Data sheet - ihr-business-im-internet.de/anwendungen/ms-visucom/bilder/firma70/EN/zubehoerprofi/276.pdf

Price: 15€ per sq meter of 20mm thick - on campingshopwagner.de/product_info.php?info=p4340


  • simple to put
  • good sound insulation


  • may be difficult to obtain outside of Germany
  • mostly good for flat parts, otherwise time consuming

Buy Reimo X Trem isolator:

Aeroflex FIRO

Aeroflex FIRO insulation

Aeroflex FIRO insulation applied in van

Thermal conductivity at 0 °C: 0,034 W/mK

Sold as roll.

Data sheet: aeroflex.nl/en/products/aeroflex-firo.

Price: usually around 10€ per square meter when 19mm thick.


  • simple to put
  • good sound insulation
  • different thicknesses available
  • self glueing available
  • clean & aesthetically pleasing


  • mostly good for flat parts, otherwise time consuming

Tip: buy self gluing version to make things simpler.

Example usage on a Ford Transit : verpiss-dich-von-meiner-veranda.de/post/188/wohnmobil-isolierung/

Buy Aeroflex FIRO:

Armaflex (product of Armacell)

Armaflex insulation

Armaflex insulation applied in van

Thermal conductivity at 0 °C: 0,036 W/mK

Price: 10€ per square meter - ebay.de/itm/like/271583864528

Sold as roll.


  • simple to put, just cut to the shape you like
  • good sound insulation
  • different thicknesses available
  • self glueing available
  • clean & aesthetically pleasing


  • mostly good for flat parts, otherwise time consuming

Armaflex "AF series" - armaflex.com/www/armacell/INETFAQ.nsf/IDP/478F84DCC0A98ED6C1256CD700600264

Buy Armaflex:

Polyurethane foam

Polyurethane foam insulation applied in a van

Thermal conductivity at 0 °C: around 0.025W/(m K)


  • good sound insulation
  • can expand 50 times more, i.e. a 1L of product can produce 50L of foam
  • can "fill" an empty area, filling even the smallest cavities


  • can deform the car body when added
  • prevent future car body work (in case of accident) on parts having that foam
  • compresses over time? (TBC)

Polyurethane on Wikipedia

Thin multi-layer insulation

Thin multi-layer insulation

Thin multi-layer insulation applied in van

Price: 5 à 15€ per square meter, according to number of layers & materials used.

Pros: very thin.

Cons: - poor sound insulation - fragile, so must covered by something almost straight away to avoid damaging it

Example usage: isere-evasion.com/isolation.htm

Example product: castorama.fr/store/Isolant-mince-multicouche-17-prod250073.html

Which country use it in converted van:

Denim isolation

Denim isolation

Denim isolation applied in van

Pros: eco-friendly.

I just came across that material & thought it probably was worth mentioning it as it's very eco-friendly. Further research on its characteristics is needed though.



More insulating materials

  • "Trocellen"
  • "KFLEX"
  • Sheep's wool

My biased opinion

I think the best is to use Reimo X Trem isolator (or Armaflex or Aeroflex FIRO) and afterwards add some sprayed cork in the parts you could not cover.

By adding sprayed cork on these parts that couldn't be covered, you'll reduce the thermal bridges, or completely eliminate them if you put enough layers.


  • Have you made a decision on what to use?
    – Alaska Man
    Feb 28, 2017 at 3:50
  • Yes, I used Armaflex. I liked the fact that it's easy to install (cut & apply), very clean (didn't need to apply a "proper" wall straight after, it's a good sound insulator, it's affordable, it comes in different thicknesses, it does not burn easily, and so on. I might apply sprayed cork later in the difficult parts that I couldn't cover.
    – Adriano
    Feb 28, 2017 at 21:57

Given that the main criterior for insulating a van are going to be weight and thickness (so that you don't lose too much space inside), I'd suggest you want the higest insulation-density you can get - so something like Celotex or Kingspan or other similar brands of rigid foam-board insulation.

They'll be more expensive than other types, but also get you a lot more insulation for the same thickness (or less thickness, and weight, for the same amount of insulation)

  • 1
    Makes sense. Do you have links to some technical documentation regarding those materials?
    – Adriano
    Aug 15, 2016 at 13:08

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