We've received many questions about insulation throughout our Airstream restoration process, partly because there are a few different options worth considering and even more opinions on what’s best.
On our first Airstream restoration we did a ton of research and ultimately decided on spray foam insulation. Based in Bend, Oregon, we get some chilly winters and warm summers, so we wanted our trailer to be as toasty/cool as possible and per inch of insulation, spray foam is the best. You can buy home kits, but it's a very messy job so we were happy to pass it along to some local professionals. Our prep work included covering the windows and placing the wiring firmly in place and out of the way. Once the spray foam was complete, that's when our mess began. In order to install the interior skins, some of the spray foam had to be leveled out so the interior skins could sit flush to the ribs and some wires had been pushed out as well, so there was a bit of cleaning up to do.
A few things to note: 1. This is not fun, it's tiring, messy work 2. Watch out for your wires hidden in the spray foam, you don't want to nick them 3. You'll most likely have to grind some spray foam off the ribs as well 4. Your wiring and appliance placement really should be done before the spray foam is in, this does mean that it'll be difficult to change or fix anything in the future. One last important thing we noticed, if you're working with an older trailer, the pressure from spraying of the foam could push on the exterior skins, creating bumpy aluminum from the outside (patched areas seemed especially prone to this). This might have also been from using a commercial grade sprayer and inexperience (spraying a trailer) on both our sides.
- It'll keep your trailer toasty!
- You can pay someone to do it for you (well, a portion of the work)
- There is still a lot of work that has to be done before and after spray foam
- It'll be a real pain in the butt if you need to access any electrical wiring in the future
- It can cause dents in your exterior skins
Reflectix & Traditional Fiber Glass (or other batt material)
After our spray foam experience, we have shifted to Prodex and fiberglass insulation or mineral wool or batt. We start with a layer of Prodex, run the electrical wires and then add in a layer of R13 fiberglass that we pull in half so it fits in the narrow cavity. Prodex gives a good r value for how small it is, and the fiber glass is tried and true. It is half the price of the spray foam, isn't as permanent as spray foam if there was ever a need to get back into the wall cavity and fix wiring. The Prodex is a foil sandwiched foam, and the gap created by the wires between the two forms of insulation offer an air gap
If you get online and research, you’ll inevitably feel overwhelmed with all the choices and opinions on this subject. Just know, that by getting in the walls and cleaning out the old nasty pink stuff, you’re already making the most important decision in this process.