Insulation Thickness Query

[reptilemarine]

I am looking to build a small camping trailer just for sleeping in when I go away to model plane flying events. What is considered the average insulation thickness to sustain relatively warm conditions inside the trailer un-heated? I see 3/4" used here a lot, I am thinking of 1" ridgid foam insualtion all over. The trailer will be 4'w x 6.5' long and 3' tall. I am based in the UK so camping from 10'c to 20'c on average.

[tony.latham]

You will never notice the difference between 3/4" of insulation or 1". But you'll notice that you can't sit up in a 3' tall camper.



Build it 4' tall.

Tony

[Pmullen503]

The need for ventilation and fresh air means the return on insulation diminishes very quickly. That said, 3/4 or 1" is definitely worth it.

[MickinOz]

3/4 is plenty mate.
In 10C overnight temps here in Oz, in my uninsulated 9 x 5, I sleep with only the screen door closed. (My doors split, so the glass leaf can be opened separately.)
Zero Celcius is another matter entirely, so I wouldn't advocate for no insulation at all in a UK build, but it really is surprising how the small space warms up with just body heat.

[MickinOz]

P.S. I agree with Tony - shoot for 4 feet high. By the time you lose a bit to the floor, and lose a bit to the ceiling cavity where your insulation will go, you may only end up with 3 feet 8 or 10 inches. Three would be pretty low.

[Capebuild]

I know there are a bunch of manufactured teardrops that don't use insulation in the walls or ceiling. Some insulate just the ceiling (given that heat rises).
From what I gathered from other builders here on TNTTT, most use 3/4" in the walls and 2" in the ceiling (this is the configuration I had used in my trailer). Condensation can also be minimized by having a well insulated trailer. But to your original question, I'm with Tony... his comments. The difference between 3/4 and 1 inch in the walls is probably negligible. I'd think a thicker insulation in the ceiling would make more of a beneficial difference.

John

[Onajourney]

I went with a 1” insulated walls, ceiling and floor and here is why. R Value with 1” Styrofoam board insulation.
¼” plywood exterior = .31
1” Styrofoam = 5.0
¼” plywood interior = .94
Total R Value 6.25

A popular ¾” wall method
¼” Exterior plywood =.31
¾” Styrofoam = 4.0
1/8” interior Plywood= .15
Total R Value 4.46

Not factoring in the interior skeleton or “framing”, 1” insulation and ¼” ply in and out will give you an ~40% increase in R value compared to ¾” insulation and 1/8” interior which I think is significant. Please correct me if my calculations are wrong. This of course also doesn’t factor in windows and doors which knocks it down some. There is a sound and sturdiness benefit as well as a weight detriment.
I got the values here but there a ton of calculators online.
https://www.coloradoenergy.org/procorne ... values.htm

Oh, and without question, 4” tall walls. IMO

[philpom]

We ended up with almost 1.5 inches in the ceiling and 2" in the floor, the walls are just 3/4" plywood. The door is insulated minus the window and the windows are single pane 30"x20". Our first trip is soon and the forecast has lows in the upper 20's F. We'll see but a test here at the house had it pretty warm inside in when it was in the 40's outside. I obviously see a benefit in wall insulation also, it just depends on your build. Since you need to vent for fresh air it kinda creates a pickle...

[pchast]

I have a 'foamy' of 1.5 inch foam. It stays warm for me.

As far as your height...
Do yourself a favor. Measure your height sitting on the thickness of your mattress..
Then add about 3 inches over your head. Get a friend if need be to read the
measure you lean against.