Insulation on a budget and wall framing options

[TygerCub]

The best way to determine the most cost efficient insulation is to figure the cost per square foot. What's the inner dimensions of your bus? How long, how tall? Are you insulating the roof too? Once you figure out the total square footage, determine how thick you will make the walls. This will give you cubic footage that can be used to determine the actual cost of expanding foam. If you go with the "great stuff" foam, don't use the cans. Buy the slow rise canister system from Handi-foam, Tiger-foam, or Eco-foam. That will be MUCH more economical than buying all those cans. If you send me the measurements, I can do a cost breakdown worksheet for ya.

[kamoo]

I used the rolls on my back wall because getting the rigid in there would have been about impossible. Rigid 3/4" doubled up on the sides where the windows were removed and used expandable foam (Great Stuff) in the tight areas on the back wall. If I was using it to camp or lived up north I would have spent a little more time on this and taped the joints etc but I wanted more sound insulation than anything else. I'm covering my framing with 1/2"-3/4" ply. The Thomas body bends inward where the windows start so I tried to get my framing to keep this as level as possible and flush with the wire chase, looks stupid but I think it'll work. 2x3 on the bottom, 1x2 on top and will use all 2x3 for all framing, it was too hard to get a straight 2x2. Some pictures are here:
http://s626.photobucket.com/albums/tt34 ... 080256.jpg
http://s626.photobucket.com/albums/tt34 ... 240227.jpg
http://s626.photobucket.com/albums/tt34 ... 230215.jpg