I would plan to insulate, however. Have any of you had any issues with thermal bridging of the structural aluminum with the foamboard insulation?
You pretty much have to insulate with an aluminum camper shell for sure. You should also post this question over on the Ovrlnd Only thread. Everybody’s insulating just a little bit differently.
Personally, I chose to use a double foil faced quarter inch closed cell foam sheeting that went on top of the frames and left an air gap to the skin with a Coroplast
inner (edit: whoops, I meant OUTER) layer (except for the roof which is just the foil/foam). Its been effective for thermal bridging and general insulation. To a large degree I did this because I’m more concerned about heat living in Phoenix and weight given 1300 pounds of payload. The camper temps stay 10 to 15° above the outside so far down into the high 30s with no heat going. Would definitely need to turn on the Wave 3 heater in the 20s or lower. We also have the thermal liner for the tent walls.
The challenge is that you cannot eliminate the thermal bridging from the the bed slideout area on the sides as well as places where your truck bed wraps over and the camper sills sit on rail. I have a Bedrug which helps the bed itself, but there’s always going to be enough thermal bridging to mean you can’t be fully insulated truly. I will say that it certainly makes a difference even with the remaining thermal bridging. And, it’s good enough that running a Wave 3 heater works well.
If you are really concerned about the most effective insulation, I suppose something like spraying Lizard Skin over the bed and the camper shell and then putting some protective layer or further insulation over that would give you the absolute best insulation coverage, but it’s a messy hassle.