Insulation options with little space
Hello everyone! First time posting here. I’m working on a project and have reached the stage where I need to decide how to insulate it. Reading the information on this website, obviously one of the first tenements of insulating is that “Thicker is Better.” However, I’m looking for some advice on what to do when I don’t have the option to go thicker.
For context, I’m renovating a 1976 Airstream for full time living and travel. This means we could potentially end up in any climate in America, although we currently live in zone 5. The difficult part is the thickness between the wall/ceiling studs is very small: about 1 3/4″ to 1 5/8″. Currently, I don’t see a way to accomplish any significant R-value. We do have more space in the floor for insulating, but I’m not sure if it will do us much good. There’s about 6″ in the center of the Airstream, but the edges curl up to meet the body on each side, which reduces the available space.
Furthermore, regarding the materials: the shell of the trailer is entirely aluminum (outside skin, studs, and inner skins) although the inner skins are coated with a vinyl material. The frame is steel and the subfloor (which slots between the frame and shell) is plywood. Part of the difficulty here is dealing with the transfer of heat/cold through the aluminum studs to the interior skin. I have some idea how to eliminate this. My father is familiar with a ceramic stray-in insulation used in cars which I’m considering spraying over the studs in a thin layer. It’s not much, but I think that’s all I’ll be able to fit between them without altering the fit of the interior panels.
So, yeah. That’s the rundown of the project. I’m just a little lost and overwhelmed by all the insulation options and choices. For instance, I’m not sure if it’s better to leave some dead space/air in the cavity or pack it all with insulation. All in all, I would love some help figuring out how to make this the best insulated house it can be under the circumstances.
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Replies
Maya,
First of all, owners of Airstream trailers are famously obsessed, so there must be forums on the internet devoted to Airstream restoration. That's where you should direct your questions, because I'm certain that you aren't the first person to face this question. Others have come up with solutions.
I am neither an Airstream owner nor an Airstream expert, but my go-to solution in your case would be closed-cell spray foam. Good luck with your project.
Closed cell spray foam really seems like the go-to answer. Once sprayed it can be shaved to meet the exact curve required. Fiberglass bats might do some good, but it would be super hard to get that tacked in place sufficiently to allow the interior cladding to be put on, and you'd get variable gaps at the edgs.
Keep in mind you need flexibility: whatever insulation you use can't crack if flexed when the trailer moves or the metal expands and contracts with temperature.
You want to think about both the air space (insulation is better), and those ribs which are going to conduct a LOT of heat. The metal is way worse than wood, and wood transfers heat. Even a small thermal break would help, perhaps add sticky roofing material on each of the ribs, to create a small thermal break between the rib (cold) and the interior paneling.