This is the place to ask questions, share your build photos, and get help with insulation materials, methods, moisture control, vapour barriers, and everything in between.
Whether you're aiming for a cosy winter cabin or just trying to avoid summer sweat puddles, you're in the right place. This thread links to our best guides and tools to help you insulate smartly, safely, and efficiently.
Helpful guides to get started:
Helpful tools to get started:
Roaming Home - The Van Conversion Book
Most Common Questions in This Category
What’s the best insulation for a van?
PIR foam board (like Celotex or Kingspan) is the most efficient and commonly used. Sheep’s wool is eco-friendly and moisture regulating.
Should I insulate the floor?
Yes – PIR under the ply floor is standard. It prevents heat loss and cold feet in winter.
How thick should my insulation be?
25mm is typical, use up to 50mm if space allows.
Can I mix insulation types?
Yes – many people use PIR board for large flat areas and wool for awkward gaps.
Do I need a vapour barrier?
Depends on your insulation type (whether it is moisture regulating already). Optional with natural materials like wool.
How do I stop condensation in the van?
Good insulation, proper ventilation (roof fan), and attention to thermal bridging. Keep the van interior warm.
What’s thermal bridging and why should I care?
It’s where heat escapes through uninsulated metal (e.g. ribs). Always insulate over and around metal to avoid cold spots and condensation.
Can I use spray foam insulation?
It’s an option but harder to DIY as you need a lot. It has also been known to cause problems like panel warping. Closed-cell is better than open-cell.
Is sheep’s wool a good option?
Yes – it’s breathable, sustainable, and regulates moisture. But it needs airflow and can retain smell if it gets wet.
Can I just use Reflectix?
Only as a radiant barrier – never use Reflectix on its own. It needs an air gap to work properly.
Do I need to insulate window panels?
Yes – use insulated window covers or custom-fit blackout thermal panels.
Should I insulate inside the doors?
Yes – especially the rear doors. Use wool for flexibility.
Do I need to soundproof as well?
Optional, but adding sound deadening mats (e.g. Silent Coat or Dodo) helps reduce road noise.
Is insulation flammable?
Some foam boards are. Always check fire ratings and avoid cheap no-name boards.
How long does it take to insulate a van?
Most people spend the best part of a week on insulation.