Interior insulation

Reflectix is not much good as far as insulation goes. It makes a convenient windshield cover.

Sheet foam insulation may be an option. It's easy to work with and readily available.

The highest R value per inch of insulation board would be Polyisocyanurate with an R value of 6.5-7per inch. I don't care much for working with it as it crumbles an makes a mess.

Extruded Polystyrene (XPS) is my preference but only R-5 per inch.

By far the best solution is:

https://www.amazon.com/Reliable-Outdoor-Gear-Professional-Compass/dp/B0759LHB92/ref=sr_1_4?keywords=Compass&qid=1560192380&s=gateway&sr=8-4

If I get unbearably warm, I point the little pointer at "N" and step on the long skinny pedal....

interior insulation is not going to help much. Far better to put even a plastic tarp on the exterior with an air gap. Use "space cloth" if you can find it.

pianotuna wrote:
interior insulation is not going to help much. Far better to put even a plastic tarp on the exterior with an air gap. Use "space cloth" if you can find it.

Yep. since you have the reflectix put it on the outside with the shiny side away from the unit.

I've done what I can on the outside. Was really hoping somebody had an idea of some way to insulate the ceiling on the inside. Right now I'm covering the ceiling with foam board which is R5 at least, but having trouble getting it to stick using double sided tape. I live full time outside Austin because of my job, so no option to move north yet. Thanks federal government for making people specifically born in 1955 wait longer to get full social security.

Hey Nana,

I feel your pain. I spent a Summer in Las Vegas Nevada working a contract job. It was miserable. 120F outside and only one roof air.

I could not wait to get out of there.

While I don't plan on repeating that experience I am putting over 2" of closed cell polyurethane insulation in the floor, walls and ceiling in my new rig.

Good luck.

Our trailer is well insulated up top except for the slide. I could feel the heat on my head. I laid a length of reflectix on the outside roof and noticed a temperature drop right away.

Use a screw that is about 3/8” longer than foam board with a fender washer.