Daniel Groves

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Planvan: Insulation and Vapour Barrier

Published: 4 November 2018 · Tags: planvan, van

Combating the cold in the UK winter with insulation and a vapour barrier.

A few months back I bought Geoffery, my 2010 VW T5 with the intention of converting it into a camper over a period of time. In the UK we’re now going into the autumn and winter months. It gets cold here, but a correctly insulated van should remain a sensible temperature overnight year round. It’s important to remember that before you can insulate you will have to add any noise management to the van first.

 alt: First skin of Thermawrap is taped down to stop it moving while isntalling the next layer of insualtion.
First skin of Thermawrap is taped down to stop it moving while isntalling the next layer of insualtion.

The insulation I’ve opted for is made up of three layers; an outer layer of Thermawrap to help reflect the summer heat back, then a layer of Celotex where space allows and recycled plastic in the hard-to-reach areas, followed by another layer of Thermawrap sealed with aluminium foil tape to create a vapour barrier. While this system isn’t the fastest to install, but it should help to keep costs sensible while providing excellent thermal properties.

 alt: Middle layer of insulation goes in. Behind the recycled plastic is a layer of 50mm Celotex. Recycled plastic makes up the gap in front before the Thermawrap vapour barrier goes in on top (partly installed in this shot).
Middle layer of insulation goes in. Behind the recycled plastic is a layer of 50mm Celotex. Recycled plastic makes up the gap in front before the Thermawrap vapour barrier goes in on top (partly installed in this shot).

Work began immediately after finishing the sound deadening with a trip to Wickes for three 20m rolls of Thermawrap, four 45m roles of aluminium foil tape, a sheet of 25mm Celotex, 50mm Celotex and two rolls of recycled plastic insulation.

 alt: Celotex and recycled plastic installed into the rear quater panel.
Celotex and recycled plastic installed into the rear quater panel.

Starting the walls initial progress was fast, making up an initial layer of Thermawrap to sit flush with the outside of the van, shaped carefully to contour with the van and fit around the structural material. After this, I started shaping the thickest Celotex that would fit into each area and packing out the bulk of the space before finishing off any inaccessible areas by stuffing it full of recycled plastic. With this system, the drivers’ side wall and both back doors took around a day to complete, while the other wall I did over several evenings, but probably took around the same amount of time to complete. This side is slower the as the door mechanisms need boxing off to make sure no fibres from the loose insulation block them up over time.

 alt: Left-hand quater panel fully vapour-sealed.  alt: Right-hand quater panel fully vapour-sealed.
Rear quater panels completed with a mix of 50mm and 25mm Celotex, and a fully fitted vapour barrier.

When it came to the roof I recruited some help from my friends Luke and Louise. With a team of three it took us around an hour to stuff the roof frame with recycled plastic, and then another two to fill the panel areas with Celotex (or recycled plastic for the small area where we ran out of Celotex), build up the vapour barrier, and replace the rear ceiling panel. All in the two L’s spend about 4 hours helping me.

 alt: Rear door before insulation.  alt: Rear door after insulation.
Rear door before and after insulation.

After they left I finished the vapour barrier for the front half of the payload area and the cab roof in around 4 hours. I then spent another hour juggling panel clips and roof panels to finish the vapour barrier for the front half of the van and reinstall the other roof panel and the headliner in the cab.

All in insulation and sound deadening probably took me three days of time, mostly in 2-3 hour increments. With that done I’ll probably leave the van alone for the winter now as I keep using it for an upcoming week in Cornwall and a bunch of shorter weekend trips.