Trailer Insulation

Hey Guys -


I'm getting ready to insulate my 6x12 enclosed trailer and would like some recommendations:


1. Should I fir out the walls an extra 1/2" so I can get another 4 R's

2. Did you insulate nearly every square inch of the walls and ceiling before you re-skinned the inside?

3. How many R's is enough for fall and spring camping?

4. What material did you use?

5. How did you glue the insulation to the roof of the trailer?


I have 2 goals for this projects. I'm looking for a dry, semi warm sleeping area in the spring and fall rides with my son and looking to deaden the sound inside the trailer. I plan to run new lights and some outlets when I need to run the genny.


Thanks for the advise,



It isn't cheap, but it's hard to beat the R value of spray foam, I've fallen in love with the stuff after using it on a few projects.  It's insulation, vapor barrier and sound deadener all in one.  Fills in all those cracks and cavities you'd never be able to with panel or fiberglass.

Yes, spray foam would be the best. But if you use the fiberglass or foam, leave a gap between the insulation and inside edge of the skin, it sweats like crazy and will soak into your insulation. And dont go all the way to the floor, leave a gap there too, and a drain hole, so collected water can pool below and drain off.

ditto on the spray foam.  I just built a new house and sprayed it myself.  put two inches on the walls and on top of the ceiling sheetrock.  then fiberglass over it.

I looked into spray foam with mine... thing is, after talking to a few vendors... you'll find vendors who say "YEAH THIS STUFF'S GREAT WE'LL SELL YOU ALL YOU NEED EASY DO-IT-YOURSELF PERFECT FOR RV'S EXCELLENT CHOICE THANKS FOR CALLING US"...


Then you'll talk to someone who's actually interested in getting you good results rather than just selling you foam.  It's hard to control expansion, and when you've only got an inch or so in the walls to work with, you may end up bowing out the sides or end up needing to trim off excess overspray to get things to line up again. 


For insulation, I used 1" foil-backed iso board.  Easy cut-to-size, then foam in the gaps and ribs with Great Stuff. 

Electrical, wire that in before you insulate.  Plan out where you're running wires.


My whole trailer build is here:


Used a "motor base" to bring power in from the gen or shore power.  It's the opposite of a wall outlet, just plug an extension cord into this.



Insulation, like I said, cut the isoboard to fit and stuff it in there.  Blue junction box is where one of the three duplex 120V outlets goes.



Thermostat on the wall for the furnace, another 120v outlet, and great-stuff foam to fill in gaps and lock in teh isoboard.





Ceiling was the same way.  Pull the paneling off, cut isoboard to fit, and stuff it in there.  Doesn't have to be pretty.



Furnace in the back corner, copper tubing for the propane burner, 12V from a deep-cycle battery for the blower.



I've been out in this setup in the winter at 10k feet and the furnace and insulation have no problems keeping the inside comfortably warm.  Battery can run the furnace through the day so I don't have to fire up the generator for day-trips, and with a decent battery charger it'll only take a few hours in the evening to charge the battery back up.




Thanks for the info SnowMule. That is exactly what I wanted to know.

I am more curious about sweat concerns..I live where the weather can get crazy. I was getting ready to do my van.

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