We did 3 types of insulation:
R-Max Rigid Foam Board
Rockwool "Safe n sound" stonewool batting
After intense research over insulation we decided on R-Max rigid board insulation for the majority of the van. This has reflective properties and the highest r-value per inch we could find.
Roxul for the sound deadening qualities and for the "stuffability" factor for the hallow channels.
Spray foam for filling in around the R-max and helping it adhere. Spray foam is great for holding this in place once dried. Spray foam also for channels that we couldn't shove the Roxul through.
Measure the spaces and cut each foam board out to match, allowing a gap all the way around for spray foam. We layered as much of the foam board as we could. About 1-3 sheets deep (of 1" thick sheets) depending on how deep the interior spaces allowed for. The bottom of the walls we got away with 3", the middle 1-2", and the top 1". We built out our walls so we actually were able to throw a 1/2" thick piece of R-max (rigid foam) on top of it all. Spray adhesive kept it in place temporarily and spray foamed in to permanently secure it.
Pulled Rockwool through the wide channels, being careful not to dense it up too much. You want it to still maintain airspace. Spray foam went in the ceiling ribs.
Windows were insulated with a insulating fabric that has two double sided reflective layers and thing batting to create an airspace. Read more on the Windows page.