Why insulate the sides of a Teardrop?

[Oldragbaggers]

Climate is a huge factor. In a dry climate the moisture will dissipate into the air more readily. Here on the east coast, when the humidity is high, it just hangs on everything. And it hangs to cool (uninsulated) surfaces much more.

[citylights]

So condensation doesn't occur in the bottom of the mattress. .

Hmmm... So I have some extra insulation from the roof. I had stuffed it into my garage doors to insulate them from heat while I was working in te garage, but I guess I will cut it and glue it into the spaces beneath my tear floor. Easy solution. Thanks.

[KCStudly]

Welcome to the forum, and good luck with your plans!

Insulation fills the gap between thinner inner and outer wall skins making the whole unit stronger, lighter, warmer, cooler, and more quiet than straight ply.

Think about the drive shaft in your car (okay, if you have front wheel drive, think about the CV shafts). They are hollow. The strength is in the outer fibers. The outer surface of the material does all of the work and the farther apart you put these fibers (the bigger the diameter of the drive shafts or axles) the stronger the walls (axles, drive shaft) will be with very little weight gain.

My walls are 9 ft 8 in long (plus hatch curve over hang) x 4 ft 1-1/2 inch tall and will end up right at 1-3/4 inches thick (5 mm inner ply, 1-1/2 inch thick foam and cedar subframe, to be covered with No. 12 cotton duck and paint (about 1/16 thk composite skin). Currently, w/o the canvas skin, I can lift and manipulate my walls by myself with relative ease and have no concern whatsoever that the cabin will be extremely rigid when assembled.

Why on earth would you double up 3/4 or even 1/2 inch thk ply? That is a tank! Think airplane.

No offense intended. I'm not sure that I have achieved veteran status here on the forums yet, but I've been around long enough to have observed the experiences of many, many people and to offer this advice based on their learned feedback.

Please do yourself a service and study up on the construction techniques that have been used in the "Build Journals", "Teardrop Construction Tips and Techniques", and "Foamie" sections. (There are a lot of other forums here that you may also find useful.)

Build light and smart. Plenty of room for a family of 5.

The strength is in the shape and style of construction... the sum of the parts, not just brute materials.

[len19070]

I kind of hit the middle ground on insulating sidewalls. (I always do the floor & ceiling)

I cover all my interior walls with a Foam backed rug.







Even though "Rug" has no "R" value it still has insulating qualities. (your winter coat doesn't have an "R" value either, but it works)

Its quiet, a nice interior finish, does an nice job insulating, takes up little or no interior space, I get no condensation and the best part is, it can be added at any time.

Happy Trails

Len

[citylights]

I don't plan on insulating my walls. But then again I plan on doing either two pieces of 1/2" or two pieces of 3/4" plywood for my walls. I will be insulating my rood and floor just because there will already be voids based on my design. But if I insulate my walls I will just be losing precious interior space. I plan on my family of five sleeping in there, so interrior space is at a premium.

Additionally, being here in HOT AZ more windows, vents and fans will probably be better than the benefit of that thin piece of insulation.

Idea that I had, but have not seen on here. I almost did it with mine, but decided not. It is a variation on skeletonized plywood walls, but I think much easier to construct.

Use a drill and 8 inch hole saw to skeletonize the 3/4 plywood side walls. Stagger the holes to maximize the ventilated space. Maybe use 3 inch door knob hole saw for smaller spaces to fill in. Just make sure to leave a minimum space (to be determined) between holes for strength structure. Use the same hole saws to cut insulation disks for the holes. Skin inside and out with 1/4 inch ply. Instant easy lightweight and super strong insulated construction.

[KCStudly]

Use a drill and 8 inch hole saw to skeletonize the 3/4 plywood side walls. Stagger the holes to maximize the ventilated space. Maybe use 3 inch door knob hole saw for smaller spaces to fill in. Just make sure to leave a minimum space (to be determined) between holes for strength structure. Use the same hole saws to cut insulation disks for the holes. Skin inside and out with 1/4 inch ply. Instant easy lightweight and super strong insulated construction.

Sounds like a plausible idea at first. Maybe use one size up to core out the insulation so it fits more snugly. But when you realize how labor intensive it is, and the fact that it will weigh a lot more than the standard skeleton method, it kind of looses merit. Sorry, I don't mean to rain on your thought process, but I speak from experience.

I liked the idea of minimizing frame work in a foamie and routed out a ton of pockets in foam to sink in wood blocking hard points. Each one fit and glued, weighed down and left to cure. Took a long time, a lot of work, and only saved me a few pounds. Sounded good, and in my case did save weight, but was probably not worth the extra effort, in my experience.

Also, it is important to have a record of and know where your hard points are in case you want to add features or remodel later. Documenting where the foam holes are vs. the wood would be a serious undertaking!

$.02

[2bits]

I built my Woody teardrop with 3/4" plywood walls and it would freeze you out in the middle of July in the sun with a black aluminum roof with the high fan switch broken! No worries during the day but regarding condensation in the cooler nighttime, open the windows and roof vents more on more humid days to increase the dehumidification but still, the thing is sitting there at the campsite, in the elements. It's gonna feel the humidity regardless.

So there are two schools of thought, to be blunt and VERY high level...
1. Leave it bare wood or painted so it will be able to dry without the sealing in the moisture
2. Seal it so there is no penetration of moisture to begin with

Keep reading, and make your choice!

As far as insulation, it is moot, as the smallest heater and AC unit will be well beyond the capacity to maintain the desired temp.

[Oldragbaggers]

For better or for worse I chose option 2. My tear walls are epoxy sealed inside and out (glass cloth on the outside, resin only on the inside). Hopefully no moisture will get into my walls. If it does, I guess I'm hosed.

[2bits]

Becky, I was hosed because while I put three layers of polyurethane all around, I neglected some parts of the end grain which is probably the MOST important part! Luckily it was repairable! That's partly why my next one was all metal construction, frame and all (Plus I did not have a garage any longer)...

[Oldragbaggers]

I was paying attention when I read all those posts talking about sealing the end grain, so I seal EVERYTHING.....and I do mean everything. Heaven help the drop of water that somehow manages to get into the wood of my teardrop. It will be trapped forever.

[atahoekid]

I want to echo what KC said.. I built my trailer with what are essentially foam composite walls. 2" pink foam, fiberglass and epoxy outer skin and 5mm ply as the inner skin. The walls which are over 12' long were very easily picked up but hard to handle only due to the size. The Road foamie is very quiet inside and very comfortable temperature wise without any condensation issues. Even in a Oregon rainstorm, the inside was perfectly dry and comfortable. The weight of plywood and tendency toward rotting if not perfectly sealed are what drove me away from a "conventional" build, but the aforementioned benefits plus others are what sold me on the idea. Just my two cents

[rowerwet]

go wth a foamy for cheap quick build and light weight, or go with a carpeted interior, instead of insulation. I have 3/4" foam in my walls which are 1/4" ply, 1x2" glued flat (3/4" thick), 1/4" interior walls. my roof is uninsulated, and noisy in the rain. I notice the condensation thing also in the cool mornings on the roof