Insulation is a hot topic among campervan enthusiasts. There's buckets of opinions floating around out there. However, it seems that there are two favourites used by most campervan builders. The first being a medley of custom cut panels of ridged foam insulation, the second being spray foam.
Spray foam is more or less the quick and dirty method to campervan insulation. Spray kits are all over the Internet marketplaces so finding something to suit your needs should not prove to be too difficult. Be careful to ensure you can meet your desired surface area and depth with the kit you purchase. I would recommend checking out this campervan spray foam guide.
The pros to spray foam: Quick, Simple set-up, etc. Cons: Expensive, messy,
Rigid Foam Insulation
This is the option we eventually settled on. Why? We liked the insulation rating. We liked how easy the material was to obtain, and we liked the cost. In essence, we traded our time for a cheaper but more effective method of insulation. The specific product we used was 1.5 inch and 2 inch Durofoam.
Our first go at Durofoam proved to be more time consuming than expected, but overall we were pleased with the result. We shaped the panels using utility-knives. This strategy allowed us to rough cut a panel, shave (the Durofoam), and repeat. This lead to a really tight fit. We were aware that DIY heat cutters allow cleaner cuts, but the ability to shape the foam with a utility knife made more sense in this application.
As you can see in the picture below, we aimed to cover every surface of the metal with Durofoam. The process is actually pretty simple and does not need much explanation.
1. Install earplugs
2. Grab the nearest piece of Durofoam.
3. Place in front of desired coverage area.
4. Mark your cuts.
5. Cut and listen to the foam's deafening screams.
6. Test fit..
7. Cut some more.
9. Repeat until your van looks like this:
Advanced Durofoam Shaping Tips
The floor is a little more difficult than the smaller panels along the walls and roof. We recommend using some builders paper to trace the wheel wells and walls. Simply tape a length of paper along your desired area and trace with a pencil. I would suggest taping your paper in place to maintain some accuracy. Once your tracing is done, cut out your template and test fit. A few micro-adjustments may need to be made so take your time! Your template should be ready for transferring onto your Durofoam. Keep in mind, since the foam is somewhat pliable, a snug fit will be easier to work with than a loose fit.
You should now feel like a Durofoam ninja.
Installing the Rigid Foam in your Van
So you're done shaping and never have to think about Durofoam again. Neat! That's exactly how we felt after all the squeaking.
First, do some rust prep! How? Simple. Grind out rust spots, and cover any exposed metal with rust paint.
With your rust prep done, it's time for the install. This is the easy part. Take some spray glue and cover both your current panel, and the area behind the panel with a healthy dose, let the surfaces become tacky, and slap that Durofoam into place. DONE!
Once everything is glued you can take the process one step further by filling gaps with expanding spray foam. Feel free to go nuts with this stuff, just cut out the dried excess with a knife. Finally, we chose to finish the process with everybody's favourite, tuck tape! This stuff is magical. It's ridiculously strong, and moisture resistant. Our hope was to seal the small gaps in the Durofoam, as well as strengthen the Durofoam's hold on our van. We also chose to insulate the wheel-wells with some Reflectix insulation, although it is debated as to whether this is effective or not. We didn't feel right leaving exposed metal so we went with the additional insulation measure.
With our van now sounding like a Bentley (from the inside) we are moving onto subflooring.