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Van Build | Insulation

Man Hours: 20

Cost: £380

Tools & Materials: Celotex (5x30mm, 1x50mm, 3x70mm), Recycled Bottle Insulation (x4 rolls), Spray Contact Adhesive (x6 cans), Capital Valley Plastics Ltd Vapour Barrier (x1 roll), Timber for Batons, Wiring, ‘Sticks like Sh*t’ Adhesive

Which Insulation Approach to Use


Insulation is quite possibly the most controversial subject in van building. Everyone believes their own way of doing it is the right way of doing it. And there’s a reason for that. It is the right way of doing it, for them. There must be so many ‘right ways’ to insulate your van and it all comes down to climate, how much money you want to spend and what approach suits you. This is our way.


What I will say is, if you’re wondering if it’s worth doing, it really, really is. Our last van was warm in the winter and cool in the summer. It may be our most hated van job, but we wouldn’t dream of fast tracking it.


We've included batons and wiring in our process because these were two jobs which needed to be completed before we started insulating.


The Materials We’ve Used and Why


Celotex - A thermal board with high performance insulation. Super warm and you can buy it in big sheets and cut it to size. We used 30mm for the floor and ceiling, 50mm for the top walls and 70mm for the middle and lower walls.

Pros: Easy to use, manageable and not too messy. You can insulate big areas at a time.

Cons: Most boards needed moulding to the shape of the van. Vans aren’t straight even when they look straight (lesson learnt about the Relay). Going with slightly thinner boards may have saved us some time here.


Recycled Bottle Insulation - A insulation solution for all those tiny hard to reach spaces such as the ribs and and gaps in between the Celotex boards.

Pros: Easy to use, not at all messy and quite therapeutic stuffing it in all the little spaces.

Cons: Not as fast at filling gaps as expanding foam.


Capital Valley Plastics Ltd Vapour Barrier - The vapour barrier protects the insulation from the moisture generated in the campervan. This stops the insulation from collecting damp, smelling and causing potential rust issues.

Pros: Cheap, durable, easy to use and fast to put up.

Cons: Can’t think of any!


A quick note on Foil Bubble Wrap. After doing a lot of research on this stuff we decided not to use it this time round. We believe our money was better spent on opting for thicker sheets of Celotex. We did have some left over from the last build so we used this for the ribs. No point wasting it!


Our Process

Step 1 - Glue in Batons as the Base for the Ceiling | We’ve used batons which are just a bit thicker than the ribs of the van to give us clearance when we screw in the wood for the ceiling. We used ‘Sticks like Sh*t’ to glue the batons in. This stuff is super strong, there is no need for anything else.

Step 2 - Map out the Wiring | We worked out where all our electrical points are going to be including USB ports and lights so we can have wiring mapped out to these areas before we insulate.

Step 3 - Measure and cut Celotex boards to size | Because we chose the thickest possible boards for each section we had to spend a lot of time carving the boards to fit in with the curves of the van. In hindsight going for slightly thinner boards would have made our lives easier but at least we we know we’ll be extra warm come the winter!


Step 4 - Install Celotex Boards | We used spray contact adhesive for the lighter boards and ‘Sticks like Sh*t’ for the heavier boards.

Step 5 - Plug in all gaps with Recycled Bottle Insulation | A time consuming and yet satisfying process.


Step 6 - Vapour Barrier | We used spray contact adhesive to stick it and seal all the edges.

Now we have a big, green, warm machine! We won’t lie, we are so pleased this part of the build is behind us. We often discuss what parts of the build we’d get someone else to do if we had lots of money. When we were both throughly fed up of insulating, Laurie asked me if I’d pay someone to do the insulation next time and despite being so completely over it, I still said no. There is something so satisfying about snuggling into a warm campervan knowing that it was you that created that warmth. The harder the job, the more satisfying the result.

To see more of our Insulating process head to our You Tube page to watch our video. Don't forget to subscribe to be the first to know when our next blog and vlog is live.


Total Man Hours: 34*

Total Build Cost: £763*


*Hours includes labour but not the many many hours of head scratching, planning and shopping.

*Cost covers all materials used but not the cost of the van, tools or shipping expenses as these things will vary for everyone.

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