Page 1 of 2

wall insulating

PostPosted: Mon Nov 15, 2010 6:52 am
by egglady
How important is wall insulation? I understant why the roof and floor are insulated. Why and how are the walls constucted and covered? If the walls are insulated how thick is the plywood sides?

PostPosted: Mon Nov 15, 2010 7:32 am
by LDK
Insulating really depends on if you will be camping in [all weather] conditions. I went back and forth on it too but I finally decided to do a 3/4 inch thick solid wall. Building a solid wall would be alot easier than to build a sandwich wall construction.

PostPosted: Mon Nov 15, 2010 9:38 am
by bobhenry
3/4 sub exterior with 1/4 veneer vertical stiffners in the center are 1x3 and 1x4 at sheething joints , doors , and galley and cabinet attachment points the voids between were filled wit 3/4 blue foam and then 1/4" veneer.

At -15 windchill it is still like laying your cheek on an ice cube tray.

If you are trying to air condition as well it is worth putting in all you can, without cheating yourself out of critical floor space.

Bob


Image

PostPosted: Mon Nov 15, 2010 10:20 am
by S. Heisley
Here's the way I understand it:

There exists a friendly difference of opinion between forum members as to whether insulated walls help keep the cabin area cooler or warmer or not. Many, if not all, will agree that the ceiling should be insulated. However, most will agree that using what is called a 'sandwiched' wall does help keep the weight of your trailer down without sacrificing wall strength. The usual sandwiched wall is made of 1x2â€

PostPosted: Mon Nov 15, 2010 12:44 pm
by aggie79
[quote="S. Heisley"]Here's the way I understand it:

There exists a friendly difference of opinion between forum members as to whether insulated walls help keep the cabin area cooler or warmer or not. Many, if not all, will agree that the ceiling should be insulated. However, most will agree that using what is called a 'sandwiched' wall does help keep the weight of your trailer down without sacrificing wall strength. The usual sandwiched wall is made of 1x2â€

PostPosted: Tue Nov 16, 2010 5:40 am
by toypusher
Insulation also helps keep it quiter inside the teardrop! Just a thought.

PostPosted: Wed Nov 17, 2010 3:19 pm
by len19070
There are products out there that do have an insulating value, but because they are not traditionally known as insulators and have never been assigned an "R value"

A foam backed rug comes to mind.

Is a "foam backed rug" an insulator? Yes, definitely. What is its "R value"? I don't know, whats the "R value" of a good coat? don't know that either. But they both work well against the elements.

By all means, do the floor and roof.

But even the walls on your house have less insulation than the roof/ceiling....and there's a reason for that!

Its not as critical.

I'm a firm believer in the fact that a 3/4" solid wall with a foam backed rug glued to the inside as a finished wall is the same, weight and R value or comparable to an 3/4" insulated wall w/1/4" ply on both sides (1/8" inside may be a bit lighter)

And if your building a 4' wide trailer doesn't cut down the finished interior width as much. Real estate, even in small amounts is valuable.

The rug makes the trailer quiet as well.

I have done this many, many times with the foam backed rug, have been in both extremes in temp w/no problems.

I also think a 3/4" solid wall is much easier to build especially for the first time builder.

Just my opinion.

Happy Trails

Len

PostPosted: Wed Nov 17, 2010 5:13 pm
by Steve_Cox
Condensation on the walls, ceiling and floor will be less when it is cool outside if you insulate. nothing worse than laying in bed and having sweaty walls... 8)

PostPosted: Wed Nov 17, 2010 5:52 pm
by Lgboro
Several of the posters on this thread live in areas (like I do) that have to deal with some fairly extreme temperatures. At some times of the year here in Eastern NC I can have both uncomfortably high and low temps in the same day, so I have opted to insulate with one and a half inches of blue insulation in a stick built frame. Another reason for the insulation is I am building in AC which I consider a necessity in my climate. Its not very hard to heat or cool a space the size of a tear interior so you will find many builds with and without insulation that fit their owners needs well.

PostPosted: Wed Nov 17, 2010 6:33 pm
by angib
len19070 wrote:There are products out there that do have an insulating value but because they are not traditionally known as insulators have never been assigned an "R value"

OK, look, I apologise in advance for steering this thread waaay off topic but this comment made me think of a lovely house I surveyed last year. Minimum 500 years old and maybe more, with stone floor, stone walls and a proper stone roof about 1" thick - none of yer lightweight modern stuff here:

Image

And to please Len, here is the only insulation anywhere in the property, laid on the loft floor:

Image

Some actually had been rather nice rugs, though all were worn thin in places.

PostPosted: Wed Nov 17, 2010 6:39 pm
by jimqpublic
No experience whether this would work out, but how about a sandwich of 1/2" plywood inside with 1/4" fan-fold extruded polystyrene foam, then aluminum exterior skin? No framing or anything of that sort.

It makes a 3/4" wall but with an extra 1 R-value and 2/3 the weight of solid plywood. Since the foam is thin I don't see how you would need any framing to stabilize it. Fan-fold is designed to NOT be a vapor barrier by the fact that it has small perforations- which should enhance glue-up to the plywood.

Also, the center of the plywood becomes 1/2" from the outside wall allowing use of 1" insert moulding on the roof edge. 3/4" U-moulding would fit to trim out doors and rear exposed edges.

PostPosted: Thu Nov 18, 2010 3:24 pm
by dh
Nobody else brought it up so I will, wires can be ran inside composit walls.

PostPosted: Thu Nov 18, 2010 9:03 pm
by S. Heisley
Good point, dh!

PostPosted: Fri Nov 19, 2010 1:30 pm
by len19070
With a shallow notch in the plywood, Wires can be run through a solid wall covered with a rug also.

Happy Trails

Len

PostPosted: Fri Nov 19, 2010 2:54 pm
by Senior Ninja
We built our walls flat on the work bench. The outside plywood was 5/8 and the inside was 1/4 with one inch of foam insulation. (Probably overkill.) All the wiring was also done at that time. The floor and the ceiling also have one inch of foam. We haven't been in really cold weather, but it is cozy and warm with just body heat x2. Even with the windows cracked, it's quite comfortable inside. I slept in it by myself at Field Day in June over eight thousand feet up. I was warm enough in street clothes. I had to leave the next morning because of the altitude but that's another story. We'd say the effort to insulate was well worth the extra work.
Steve