So, I have a bit of an odd project. It is a bit outside of the box, and I'm looking for alternative approaches that stick with the theme (if the plan outlined below doesn't work, that is).
Essentially, I'm building a camper, but think "Tiny House". It will be built on a 17-21 foot camper frame. The difference is I'm going to great lengths to keep it as light as possible for two reasons:
- Camper frames aren't designed to hold the heavy weight that a true Tiny Home build requires.
- This needs to be light enough so that it is reasonable to hook up for a weekend trip. "Tiny Homes" tip the scales well beyond reasonable.
I'd like to keep the "cabin" look as well with a natural looking siding. I'm also trying to keep it as basic as possible. More like an ice shanty that may never see actual ice and more be used as a bunkhouse. It will be heated, cooled, etc... and sometimes not while parked.
For the walls:
2x3 studs will be used for framing perhaps 2' off center, and rigid insulation will be used to fill the gaps. On the outside my idea is to use an exterior ply paneling that looks something like T&G. There is a product at lowes that fits the bill. This will provide both sheathing and siding in one layer.
I would use a combination of 2" and .5" insulation layers to completely fill the 2.5" depth created by the studs. Some sort of adhesive would be used generously to glue the insulation layers to each other, the studs, and the exterior paneling. A decorative interior paneling (something thin & light weight, like 1/4" paneling) would be used and also applied with generous amounts of adhesive.
So, it's sort of like I'm creating a big DIY SIP panel that includes framing, siding, and interior paneling. The purpose of all of this is to lower the materials needed, and keep the weight down, but keep it very strong by bonding all layers together. It will after all be dealing with the forces that happen on the highway.
So with all that said, I'm sure I'm being naive about many aspects - such as a vapor barrier. My basic understanding of tyvek is vapor can pass through it, but moisture cannot.
I won't having sheathing to apply a vapor barrier to because the sheathing and siding are one layer. Is this a terrible idea, and are there alternative approaches?
Window installation is another concern.
Bottom line - I don't want to build something that is going to be a rotting moldy box in a year.