Airstream Insulation is a highly debated topic among the airstream forums. Theres spray foam, reflectix, mineral wool, fiberglass, recycled denim, foam board and more. There are so many options and differing opinions.
We researched, debated and changed our minds. We have finally decided on two layers of polyisocyanurate (PIC) rigid foam board. It’s water resistant and has a R value of 6 per one inch of thickness. We have a 1.5″ gap in the wall for insulation so we’re going to layer a 1″ and .5″ foam board for a combined R value of 9. Thats the highest we could get out of any of the products.
Roxul was a close second option and we still may need to use it for the endcaps. Mineral wool is great because its very heat resistant, doesn’t grow mold, and is pest resistant. If we split a batt to the thickness we need we would get about an R value of 6.
We decided against the popular spray foam insulation for a couple of reasons. To be done correctly, it should be applied by a professional and its very expensive. We don’t want our wiring to be difficult to get to. We’re wiring the whole trailer ourselves and trying to anticipate all our electrical needs and additions, but if we need to access it in the future we would prefer not to destroy our insulation to get to it.
Another factor that influenced our Airstream insulation decision, is that we’re waiting on all our wiring to arrive. We can go ahead and get the insulation done while we wait and we can easily run the wiring over the top of the foam board. We’ll be one step closer to putting the walls back up!
This is all in theory for now, the giant foam boards are waiting to be measured and cut. We will score them with a utility knife to follow the curves and then seal the seams with foil tape. The last step will be applying double sided tape and foam sill seal (polystyrene roll) to cover all the ribs. I’ve read a couple folks have done this and it seems like a great way to help prevent the ribs from conducting cold and heat from the outer skins to the inner skins.
We’ll update with photos and let you all know if we run into any issues as we begin the insulation process, so make sure to follow our blog to receive updates!
Here are some of the blogs, groups and resources that helped us when researching Airstream insulation –