ITTOG
Well-known member
I also think 1.5" is good enough. Only reason to go thicker is for more r value, not strength.
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Plywood camper fabrication questions (thinking of idaSho)
- Thread starter ReluctantTraveler
- Start date
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First, if anyone says they can build a better sandwiched foam panel than an engineered commercial panel, I'd say they are a few steps short to the top. Only 2 good reasons to build your own; 1. Can't get them in the size needed, 2. can't afford them. But, I'd also bet after building them, it will probably cost the same or more trying to compensate for the lesser quality.
My building the walls excuse is they don't make what I'm building and I won't even ask about the price of a custom one off build from an engineered panel provider.
When you say "studs" "cross bracing" "more glue and brad nails" there is a concern for you and your family, concerns like the loss of money on an experimental first time camper build and safety. That all sounds like wood framing.
If it must be wood framed, use screws and glue, (also consider lag screws with larger stock) brad nails shouldn't be in any frame member, they are fine for furniture or perhaps fixtures, but there shouldn't be a nail in frame members. When panels are attached they become structural surfaces, holding lateral and vertical structures in place.
I'm pretty sure all newer custom quality builds are using aluminum frames. I know you said you don't weld, box tubing can be cut to provide gluing surfaces for joints, corners and lap joints. There is VHB tape and other adhesives that bond as strong as a weld, you don't really need to weld anything. You can also add flat stock (sheet stock) as diagonal bracing at corners and ply can be compressed over while giving you a flat wall surface, all of this can be glued.
Box frames will also give you a wiring chase for electrical work. If you use aluminum box 1 1/2' or larger you can put that on 24'oc for walls and floors and ceiling, it can all meet or be offset at the top and bottom plates or rails. 1 1/2" meets the insulation foam size as well. You could run small water lines through it as well and be fairly well insulated. If you need heavily insulated, add 1/2 or another inch of foam sheet over the interior and exterior, then the wall surfaces, flooring/ceiling.
But, before you turn that box into a refer fridge, decide on the windows and door sizes and how they will be finished off at the jams. It will be easier on you if your electrical boxes are outside the wall unit secured inside, you can dress them up with trims.
I think ceiling vent fans fit 2" flange in the ceiling.
If you're going to hang stuff on the walls, spare tire, A/C, Heater, etc. use flat stock inside the wall to bolt stuff to, don't just think ply and foam will bear loads overlanding.
I'd suggest you bite the bullet and buy your insulated RV doors.
This site is full of box builds with aluminum, study them.
Building with aluminum is just as easy as with wood, easily chopped/cut, filed, glued and screwed.
My building the walls excuse is they don't make what I'm building and I won't even ask about the price of a custom one off build from an engineered panel provider.
When you say "studs" "cross bracing" "more glue and brad nails" there is a concern for you and your family, concerns like the loss of money on an experimental first time camper build and safety. That all sounds like wood framing.
If it must be wood framed, use screws and glue, (also consider lag screws with larger stock) brad nails shouldn't be in any frame member, they are fine for furniture or perhaps fixtures, but there shouldn't be a nail in frame members. When panels are attached they become structural surfaces, holding lateral and vertical structures in place.
I'm pretty sure all newer custom quality builds are using aluminum frames. I know you said you don't weld, box tubing can be cut to provide gluing surfaces for joints, corners and lap joints. There is VHB tape and other adhesives that bond as strong as a weld, you don't really need to weld anything. You can also add flat stock (sheet stock) as diagonal bracing at corners and ply can be compressed over while giving you a flat wall surface, all of this can be glued.
Box frames will also give you a wiring chase for electrical work. If you use aluminum box 1 1/2' or larger you can put that on 24'oc for walls and floors and ceiling, it can all meet or be offset at the top and bottom plates or rails. 1 1/2" meets the insulation foam size as well. You could run small water lines through it as well and be fairly well insulated. If you need heavily insulated, add 1/2 or another inch of foam sheet over the interior and exterior, then the wall surfaces, flooring/ceiling.
But, before you turn that box into a refer fridge, decide on the windows and door sizes and how they will be finished off at the jams. It will be easier on you if your electrical boxes are outside the wall unit secured inside, you can dress them up with trims.
I think ceiling vent fans fit 2" flange in the ceiling.
If you're going to hang stuff on the walls, spare tire, A/C, Heater, etc. use flat stock inside the wall to bolt stuff to, don't just think ply and foam will bear loads overlanding.
I'd suggest you bite the bullet and buy your insulated RV doors.
This site is full of box builds with aluminum, study them.
Building with aluminum is just as easy as with wood, easily chopped/cut, filed, glued and screwed.
rruff
Explorer
??? I think the norm is sandwich panels, with commercial FG skins and usually PU foam core. Edges are FG extrusions in the case TC, and some including DIY use aluminum angle. None of them have frames in the core than I'm aware of unless it's for mounting something heavy.
ReluctantTraveler
Well-known member
Well, if they don't they should have.
Seems I've seen frames being built, now I don't know about buying FG extrusions, I wouldn't be opposed to a/angle, but box is much stronger, a bit more expensive and has some benefits I pointed out.
Saying "sandwich panel" what exactly is that, foam, like blueboard enclosed with ply? Or is it blown in insulation or something else?
Then how do you get the electrical and plumbing chases?
I probably spent too much time on those TTT tear drop/cargo trailer build sites. But, if I were building a box for my truck that's what I'd do. Not the only way but a way.
Really, waaaay too much talk about thermal bridging in a camper, and covering that aluminum can be with 2 more inches of foam plus the wall material. If it's a concern there are techniques to break thermal transfer but I doubt any human could tell the difference just being inside.
Got it on your brad nails, very good.
ReluctantTraveler
Well-known member
Sandwich panel in this context typically means a foam core (XPS, PVC, or honeycomb) "sandwiched" between an exterior layer. Marine-grade plywood is a common DIY material, though I've seen some folks using composite panels instead.
Some constructed panels (like those from Total Composites) include a chase and some extrusions for mounting things, but they don't go fully from the inside to outside to minimize thermal bridging. A lot of DIY folks just run the wires internally, hidden in a cabinet, a basement (if the camper has one), or inside some sort of cable organizer. Some folks prefer this as it's easy to "service" the electrical system if needed.
ReluctantTraveler
Well-known member
I'm confused. Aside from this being on a pickup instead of a flatbed, this looks a lot like what I've been described AND what idaSHO actually did.
So, we are on the same page?
I might be in a different book. Engineered structural panels, internal frames, insulation compressed sandwiched by FG or ply and covered with FG/sheet metal exterior?
DIY= Foam board covered with plywood and exterior/interior coatings, FG, metal whatever. Made with or without a frame?
@IdaSHO do you have a build thread here?
ReluctantTraveler
Well-known member
I think so? There are, as you've noted, a handful of ways to build panels. Ask three different overland builders and you'll get three different answers on which one is best.
I'll personally be going with a wood frame and structural PVC foam core, with plywood skin and hand-laid fiberglass over top.
I really need to listen to @rruff and build a small sample panel, though.
That sounds fine, we all follow different paths but somehow get there. If you paint that wood frame material it will last longer.
IdaSHO
IDACAMPER
His ramblings will do that.
rruff
Explorer
Ambition Strikes and Everlander welded an aluminum exoskeleton and glued panels inside of it. OEV does something similar I think, only they rivet the aluminum pieces together with plates on the corners. I don't know exactly how Aterra and Scout do theirs but they have aluminum on the exterior edges. I wouldn't call that a frame... but I guess you could.
Build many and have fun testing them!
Build many and have fun testing them!