Insulating walls

[James9324]

I have been planning on designing my trailer with the skeleton 3/4 inch walls, insulating the sides and then covering each side with a 1/4 inch plywood so the walls would be approx. 1.25 inches thick. I was talking with someone about this who was just shooting down this idea of insulating walls but only doing the floor and ceiling.

I am wondering everyone's thoughts on this. Pros and Cons. Are there any advantages to insulating or not.

My original thought was for weight control, get rid of some plywood and replace it with lighter insulation.

I would appreciate any opinions.

Thanks

[tony.latham]

I have been planning on designing my trailer with the skeleton 3/4 inch walls, insulating the sides and then covering each side with a 1/4 inch plywood so the walls would be approx. 1.25 inches thick. I was talking with someone about this who was just shooting down this idea of insulating walls but only doing the floor and ceiling.

I am wondering everyone's thoughts on this. Pros and Cons. Are there any advantages to insulating or not.

My original thought was for weight control, get rid of some plywood and replace it with lighter insulation.

I would appreciate any opinions.

Thanks

I purchased my first teardrop in 2004. It had solid plywood walls and an insulated ceiling. The condensation problem on chilly nights –-even with the windows cracked-- was so bad we kept a bath towel in it for wiping the walls down each morning. I'm not sure what the finish on the inside was --I think a lacquer-- but I had to refinish it after a few years with poly.

Since 2013, I've had teardrops with walls insulated with 3/4" insulation. No condensation. I would never consider going back to a solid-walled teardrop. It's not about warmth, just condensation.

I was talking with someone about this who was just shooting down this idea...

Does this guy own a teardrop?

Tony

[Capebuild]

I had asked the same question when I was planning my build. Quite a few members had responded. Here's the link to that discussion..... you may find some helpful information there to help you with your decision.
viewtopic.php?f=2&t=73526
(unfortunately when I created the post I misspelled "insulating" and used "insulting".... The post's title being "is insulting the trailer necessary")

For what it's worth, I'm currently assembling the walls now and did insulate the voids in the skeletonized middle section with 3/4" pink board.

John

[halfdome, Danny]

My first TD I did all that framing with insulation and the only benefit we noticed from subsequent 3/4" plywood builds was the insulation was quieter in campgrounds.
I do have 2 side vents on the galley wall and one between the galley and cabin and the fantastic vent/fan.
We don't do boondocking so we are able to have electric heat if needed.
The only condensation I've noticed is on the aluminum trim around the door and that's minimal.
Whatever method you decide find a good quality 3/4" plywood with a core like this.

My supplier doesn't carry Pacific Birch Light anymore but I understand a Fir core is usually the lightest.
Don't go cheap as one of my customers would give me sheets of plywood that would delaminate when cut to size, what a pain.
I do insulate the ceiling with 1 1/2" of foam, including the galley hatch.
Danny

[John61CT]

Use the rigid foam as your core, then laminate / skin

1/4" outside, even Luan ply inside

or check out PMF foamie for super light

even thicker foam for extreme temp situations, reducing HVAC energy consumed.

Fighting condensation requires higher CFM ventilation.

[MickinOz]

If you have the time, patience and money, insulate.
Here in Oz, things are slightly different.
Materials are expensive and hard to find.
In the end I went with solid walls, made from 17mm pine plywood.
This was not a massive problem on Saturday night, softwoods do resist heat transfer a bit.
The big issue is the doors! My doors are aluminium framed, full glass (actually polycarbonate I suspect). They are highly heat conductive. They get wet!

But they also help with fixing the problem.
Having an inner screen door with security mesh, I simply opened the solid leaf during the day, leaving the screen door locked, and let the air circulate. Dry in no time.

The next one (currently chasing a suitable trailer) I am considering using 12mm marine ply - hardwood.
Hardwood is much denser than pine. It has slightly less than half the insulating value of the same thickness of pine ply.
This might be more of a problem.
Tends to depend where you live too. Not many sub zero nights here where I live.

[Socal Tom]

I think a lot depends on the climate where/when you camp. My TD has solid 3/4 plywood walls. I generally camp when low temps rarely dip below 50F, and the highs are usually above 70F, and the climate is very dry. So I've generally got a fan going, and vents and windows open, so condensation isn't a common problem. When it does happen, It warm and dry so it dries out quickly. I have a contingency plan for when I do camp in the cold, and that is custom cut blankets ( walmart fuzzy blankets) that I can affix to the walls with magnets.

[edgeau]

If you have the time, patience and money, insulate.
Here in Oz, things are slightly different.
Materials are expensive and hard to find.
In the end I went with solid walls, made from 17mm pine plywood.
This was not a massive problem on Saturday night, softwoods do resist heat transfer a bit.
The big issue is the doors! My doors are aluminium framed, full glass (actually polycarbonate I suspect). They are highly heat conductive. They get wet!

But they also help with fixing the problem.
Having an inner screen door with security mesh, I simply opened the solid leaf during the day, leaving the screen door locked, and let the air circulate. Dry in no time.

The next one (currently chasing a suitable trailer) I am considering using 12mm marine ply - hardwood.
Hardwood is much denser than pine. It has slightly less than half the insulating value of the same thickness of pine ply.
This might be more of a problem.
Tends to depend where you live too. Not many sub zero nights here where I live.

I do have the 12mm marine ply walls and it is fine in my climate but I think insulation is never a waste and if your design allows for it then do it.

Sent from my Pixel 3 using Tapatalk

[Woodbutcher]

I have built 4 trailers. The first, I insulated the floor ,roof, walls and ceiling, all with rigid foam. No issues using it, and condensation was never much of a problem. The next one was only insulated in the roof and had 3/4" walls. Same results. The third one was 1/2" floor and 1/4" walls and ceiling over a stick built frame, NO insulation anywhere. No discernible difference from the previous 2 with the exception of sound deadening. A hard rain storm in a Tear with just a 1/4" roof is like sleeping inside a drum. My current trailer is stick built, with foam insulation everywhere but the floor. The last one is a standy, sort of a canned ham style. The main thing I gathered from all these, given the time of year, the climate I usually camp in, and the lowest temps being around 32 at night. I can't say I favored one over another with the exception of noise reduction from the fully insulated ones. I would never insulate the floor again. I have never had any condensation problem under the mattress on any of them. Good luck with your decision. This is one of those questions that will get you a bunch of different answers, same as what kind of cooler do you like best.

[working on it]

I think a lot depends on the climate where/when you camp. My TD has solid 3/4 plywood walls. I generally camp when low temps rarely dip below 50F, and the highs are usually above 70F, and the climate is very dry. So I've generally got a fan going, and vents and windows open, so condensation isn't a common problem. When it does happen, It warm and dry so it dries out quickly. I have a contingency plan for when I do camp in the cold, and that is custom cut blankets ( walmart fuzzy blankets) that I can affix to the walls with magnets.

* Similar camping conditions here in N.Texas make insulation only an afterthought...which I dismissed. Like Socal Tom, I always have at least one side vent open, the computer case fans going, no matter what the temperature is.

* When it's cold outside, I attached two carpeted floor mats (24"x24") to my 3/4" thick walls, just to keep from leaning into a cold wall (there's only 46.5" space in between, and I turn over a lot, solo camping).

* When it's hot outside, I'll either open one or both awning windows and turn on the main 3-speed fan to move more air. Airflow is the key to eliminating condensation, IMHO. And when it's even hotter, I'll use my A/C + fan, for max cooling (sometimes on really hot days/nights, my trailer will get condensation on the outside, while the inside is cold and comfortable).

[dbhosttexas]

Since you are looking to build, take a serious look at building a foamie. Go a little thicker and double up to 1.5" wall thickness with 2 layers of 3/4 foam board, using lumber only at critical framing points and where you need to attach fastenerns for things like lighting or awnings and you are good to go...

Uninsulated your walls will sweat / have serious condensation issues in colder weather. Small enough space with good insulation all but the most extreme cold can be human heated just fine...

[booyah]

So my build was a little different, 3/8" BCX external wall, 1/4" Luan plywoodinside, 1x2s around all the edges (really .75" thick) and completely filled with .75" r5 foam board.
viewtopic.php?f=50&t=63145&start=15#p1132336

a small 400w heater can keep it uncomfortably warm in temps below freezing and even without the heater its not horrible in colder temps. Condensation is a rare issue, and the noise reduction at loud campgrounds is impressive!

[saywhatthat]

if the ply is r1 then you add in insulation in small holes.it will make you feel better . that about it. look into Bridge effect

[Shadow Catcher]

We have 1.5" EPS on walls and roof the advantage is insulation and sound.

[James9324]

Thank you for all the replies everyone. Sorry I haven't written back sooner but work has kept me pretty busy.

To answer your question Tony, yes, the man I talked to owns them and build them. He seems pretty set in his ways.

To answer all the climate questions, I'm from Michigan and I really love to go out west to New Mexico, Arizona and Utah. Granted these are warmer locations but I have been in Moab when it's 90+ in the day and drop to 40's at night. Also if I go northern Michigan, well it gets chilly up there. I think I would rather insulate just to have it in case.

So my plan is to use 3/4 board and skeletonize that and then do 1/4 ply on both inside and out. Which brings me to another question. I would really like Maple board in the inside however all I can find if 1/4 Maple with MDF core. So Speaking of condensation problems... is that going to be an issue?

I'm starting to cut my template out for my wall and have a small 'staycation' coming up in a few weeks when I really hope to work on this camper.

Thank you again everyone for all the replies and suggestions. All comments are welcome so keep 'em coming!!!