Decent stud material

[loaderman]

Just thinking -
3/4" by 2" wood studs, or 3/4" by 2" plywood studs or some sort of metal stud as you can get 2.25" metal studs and put them back to back.
Any thoughts on what would be good?

[Roly Nelson]

I feel that a solid wooden stud, which has all of it's grain going the same way is preferable over a plywood stud, which has 2 fifths if it's grain going across the stud, and only 3 fifths running full length. Just my 2 cents, after 60 years of woodworking.
Roly ~~

[RandyG]

+1 A 2" wide piece of ply isn't strong in the way you need in a stud.

[loaderman]

That is kinda what I thought, but finding straight grained spruce or whatever is really hard and fir seems impossible and really pricey when you can.
Any thoughts on using 2.25 inch metal studs meant for interior wall. Put 2 back to back so they become an H shape.

[jstrubberg]

3/4 by 2" is enormous for a trailer...

Most use 1" by 1" or something close to that.

[Oldragbaggers]

3/4 by 2" is enormous for a trailer...

Most use 1" by 1" or something close to that.

I disagree with this one. I used standard 1x2's, and that is what I see on most builds. Not enormous at all. And if you are putting in a roof vent or fan, I think 1x2 would be nominal for framing for that.

[les45]

I agree with Becky; 1X2 is kind of the standard for most folks. Some have split 2X4's. That is an inexpensive way to go but is a little overkill. With respect to metal studs, I could see a lot of downsides when it comes to fastening them to your walls, roof, and interior panels. Gluing wood to wood makes a lot stronger bond and is also one of the more traditional ways to fasten things in teardrops.

[RandyG]

Which side on the "H" is 3/4 and which is 2". Cause the open legs of the H would make it harder to attach anything. Why not put the open sides together and make a box and rivet them together. Or just use one piece of c-channel as a stud.

[grantstew8]

I'm ripping apart a compass caravan to build a TD. I was pretty surprised by the studs they were using: The total wall thickness is 19mm 3/4" made from alucald 1/32" about 1mm, polystyrene and 1/8" 3mm plywood composite (glued together)
There is very little studwork. In the roof it's the same. The walls are composite panels and that strength is critical: in essence the wall is three things glued together, not three separate layers tacked together.
I've been involved with the manufacture of SIPs panels for 8 years.

I'll take some photos of the walls tonight, we should have the roof off and down to a flatbed trailer
The photo below is the roof spars and the Alu-clad does not seem to be glued to the spars.

[markhusbands]

I used 1x2 select pine. (3/4 x 1 1/2)

Seems stiff.

[S. Heisley]

I used 1x2 poplar (which is really 3/4" x1-1/2"). It is available at both big box stores; and, you can pick out which pieces that you want, to be certain that they are reasonably straight. It is also lighter weight and usually knot-free.

PS. Stay away from the darker pieces, especially any with green or black on them because those pieces tend to weigh a tad more. (Most people don't know that but I do because I weighed every piece of lumber that I used.) When you are building what we build, every added ounce can matter.

[angib]

I feel that a solid wooden stud, which has all of it's grain going the same way is preferable over a plywood stud, which has 2 fifths if it's grain going across the stud, and only 3 fifths running full length.

sadly I don't have any more 'centreboard blanks' to photo for you Roly. These were custom plywood for making racing dinghy centreboards, typically about 3/4" thick and with maybe 12 plies running lengthways and only two or three running transversely, to give the maximum bending strength.

[loaderman]

I should have given a little more info.
This is not really a TTT but you guys are very helpful and thought I'd get some input.
It will be about 12 to 16feet long and about 6'4 high, and probably 6'8" wide inside. May go a little higher and slope down.
Still in design stage.
It will be used for winter camping in Canada and as such I was thinking 2" Styrofoam for R10 insulation in the walls.
Exterior covering may be canvass and paint - the idea from the foamie section.
Trying to keep this as reasonably light as I can. Under 2500lbs would be great.

[Roly Nelson]

Angib, now wait a minute, using baltic birch plywood is a different animal altogether. I love that stuff, since the interior laminations are virtually flawless, usually straight an an arrow, and can be found on many of my teardrop builds. Long live Baltic birch, the ultimate structural plywood, whether 1/2 inch or 3/4 inch, I love it. Also, it makes great laminated woodturnings, of which, I have turned, many one-of-a-kind treasures..........or failures, depending on your outlook. I understand that Howard Hughes used it extensively in his Spuce Goose airplane, the largest wooden plane ever built.
Roly, the li'l ol' So Calif woody guy........always building out of wood.

[grantstew8]

As you can see this is really a SIPs wall there is almost no vertical stud work. Ripping off the ply was not easy, it was really stuck well to the polystyrene.

To give you a house building idea of the strength of a sips panel vs timber-frame (UK) stud/stick build (US): The design load on a house wall is around 1 tonne per meter, a timber framed/stud/stick build supports 3-4 tonnes before turning to matchwood. It's still pretty good. After a fire test one of our SIPs panels were put in a test press and the gauge stopped at around 60 tonnes. It is important to stress that the two outer skins and the polystyrene are glued together and act as a composite panel. SIPs panels are also particularly good at racking. (turning a rectangle into a parallelogram with a sideways force) This is handy info you can use on a smaller scale with your TD or TNTTT