The finally weather warmed up here in Tennessee, and that could only mean one thing: time to get working even faster on insulating the trailer! 😰With aluminum being such an excellent conductor of heat, it very quickly turns toaster-oven inside this tin can as soon as the sun makes an appearance.
I decided to go with Prodex reflective insulation from Insulation4Less after reading some good things about its performance – even in shallower wall cavities than those in the Airstream.
To create the necessary air space between the outer aluminum skin and the outward-facing reflective layer of insulation, I first cut and glued hundreds of tiny foam insulation blocks to the inside of the skin. It made for a very neat modern art look by the end, but also took a very long time!
Next I cut the pieces of insulation to size (with the assistance of some four-legged helpers, as you can see in the photos) and taped all the edges to the trailer with foil tape (except the bottoms, to allow water to flow downward if any leaks arise).
After a few days of this and getting these first pieces of insulation up, the temperature is much more even inside the trailer. You can feel a huge difference between areas that are insulated and those that are not! The bare aluminum can be scorching hot to the touch, but the heat doesn’t seem to transfer inside nearly as much it did before.
Hopefully a good insulation job now will mean a lot less time running the heater and air conditioner later, and more time enjoying the fresh air wherever I may be parked. Good for me, but also good for the environment!
You guys are awesome and thank you for sharing. Did the insulation work the way you expected? Would you have done it differently or used different materials?
Thanks, Edgar! It did work really well – before insulating, we could burn ourselves just touching the inner aluminum walls on a hot day. Aluminum is a great conductor of heat and cold! After insulating, they felt warm when we were in direct sun, but never hot. We never had any issues with our interior paint peeling either, which we considered a good test!
We did two layers of the Prodex, shiny side facing in and out, to keep the cool/warm air in the trailer, and then to keep exterior heat/cold out. Having an air gap between the insulation and aluminum is critical for it to work correctly, so we used the foam insulation board cut into blocks and glued them onto the inside of the outer trailer skin. It was totally worth the expense and hard work!
We’ve heard of people using spray foam, but we couldn’t imagine it holding up well to the road vibration and what you’d do if you had to access your wiring at any point. Even for the trailer belly we didn’t use it, because we were worried about it trapping moisture against the subfloor and rotting it (again). Instead, we used some 4″ thick foam board in smaller pieces, with drainage holes drilled in it, and spaced it away from the floor a bit so it wouldn’t trap water against the wood. So much more to think about when your house rolls down the road! 😀
Thanks so much for your post on this. I’m really excited to have discovered your blog this morning! My husband and I are in the early stages of renovating our 27′ 1976 Overland and we just ripped out all the old fiberglass insulation. Whew! We’re considering using Prodex as a possible replacement and its so great to read about your positive experience. I’ve heard it’s a much better insulation for both temperature and noise than Reflectix. I also keep seeing people use spray foam as a replacement but what a nightmare if it doesn’t hold up!
A few questions about your process:
I’m looking at the third image on this post and understand you glued foam insulation blocks to the outer AS skin and then put in the precut Prodex panels. After that, did you create a second air space between the two layers of Prodex or just stack them one on top of the other? And finally, did you create an airspace between the inner skins using the glued foam insulation? With only an inch and half interior wall space I’m sure you couldn’t create all of these spaces.
Did you do anything to cover the ribs? I’ve heard of people using this foam gasket tape (http://www.homedepot.com/p/Owens-Corning-Foam-SealR-Sill-Plate-Gasket-5-1-2-in-x-50-ft-2FS/202080947?keyword=sill+gasket).
I know it’s been a while since you renovated your airstream but was wondering if you have any recollection of the specific Prodex product you ordered and quantity.
Any information you can provide will be so helpful.
Many thanks and happy travels!