First thing we did when deciding on the right insulation for Scout, was tons of research. We looked into regular rolled insulation that we would cut into sections. In the end we decided this wouldn't be as efficient for the bus with all the curves and little sections that a normal wall doesn't have. To make sure each crack, tiny section was completely covered and well sealed with insulation we went with Foam It Green, spray insulation.
We ordered two kits of the spray insulation. One kit ended up being enough for the entire bus. After spraying you have to wait a full 24 hours for the foam to expand to it's full height. After it was fully expanded we did go back and shape it a little to be able to lay the walls flat against the foam.
Since I am writing this a year after we have completed the spray foam, I can tell you with full confidence that the spray foam works! The ac/heater unit is all set up and when the ac is on the bus stays super cold and when the heater is on its a warm little toaster in there. There is no air flow or cold section coming from the walls. Even the skylight is nice and tight seals. We are so happy of the overall product of the Foam It Green spray foam. We will be using it again.
One down side I did want to say is for people to really measure well how much they need. Once you order your kits they can not take them back. If you did not touch one of your kits like it happened with us, they then inform you to sell it on a site like Facebook market or eBay. Where we did not get our full refund, even though it was recommended we bought both kits. Again we were happy it didn't run out and we had plenty to cover. Measure twice and do your research!
Watch Richard set up and spray our bus below!