I’m planning to build an 8’ by 12’ shed. All 4 walls will be 8’ high and have 2"x4" studs spaced 24" on center. What I can’t decide/figure out is: do I need to put horizontal braces between the vertical studs in the walls? Or perhaps only on the long walls, but not the short walls?
What will the outside wall material be? And do you realize it would only use 8 more studs to go with the standard 16" centers? That’s about $25.
There’s no need for any horizontal bracing. Whatever you are sheathing the wall with will provide all the shear stiffness you need. Horizontal pieces are placed in houses to provide a fire block - their structural contributions are negligible.
I’ve build hundreds of “houses” about twice as big as the shed you’re planning. We never used any horizontal bracing. Of course, we blew every single one of them up with a car bomb filled with 500 pounds of ANFO 45 feet away, so YMMV.
Does that mean all your test results are invalid, and you will have to do them all over again?:smack:
Thanks. I hadn’t realized those pieces weren’t structural. Saved me a little time.
I am envious of your job, sir. 
I’ll be using 1/2" plywood on the exterior. I had considered 16" centers, but all the designs I’ve looked at for reference indicated 24" was acceptable for a non-dwelling. It does save a little money, and it saves time too, so on balance I figure that’s the way to go.
I think that the Uniform Building Code requires either sheathing or metal cross bracing to prevent racking (I think that stucco is also listed in there, though I wouldn’t trust it.) The 1/2" plywood will be bracing enough.
Some codes require bracing when studs are 10’.
This being a shed, you might find it useful to nail long horizontal 2-bys to the studs 3 or 4 feet above the floor just to give yourself a place to screw in tool hooks, provide a ledger board for shelving or a small workbench, stuff like that. It would, of course, also beef up the structure.
Do you really need plywood? I don’t know the going price these days, but all the buildings we made used 1/2" wafer board. My buddy just made a shed about twice as big as yours, and he used 5/16" masonite.
We did do them over again. We had to repeat ourselves two to three times a week! 
It was pretty fun, but I’m a desk jockey these days. Start a new one on Monday. It’ll be equally cool, but not nearly as impressive.
Either of these will work, but make sure it’s exterior grade. Interior grade wafer board (and I presume masonite) will swell up and disintigrate if it gets damp.
You do not need the horizontal bracing structurally. However because you are spacing 24", consider your sheathing more carefully. Wider spacing should demand higher quality sheathing. OSB should be fine; I would not use anything less than 1/2" (or close to it); plywood is better. If you sheath it with the sheathing oriented so the long axis is paralell to the ground, and you use cheap or thin sheathing, and you space 24", you have a greater chance of there being gaps at the seam because over that distance one board may warp out while the one below it warps in. It is useful to put a horizontal member at the level of that seam to keep the seam tight (because you now have a nailer at the level of the seam). If you orient the sheathing vertically, it’s not an issue if the total height covered is 8’ but pay attention so that your stud spacing lets the sheathing land in the center of a stud. Ditto for the stud on which a horizontally-applied sheet will land.
According to the carpentry textbook that has been my faithful companion for many years, 5/16 plywood is ok with a maximum stud spacing of 16". (I would presume OSB would be the same. This says nothing about Masonite. I wouldn’t think it would be hardy enough, but the stuff made nowadays that’s intended as a finished exterior siding - embossed surface imitating wood - might work.)
For the 24" stud spacing the OP wants to use, 3/8 plywood is the minimum recommended. You also have to use at least 3/8 if you intend to finish off the exterior with something like wood shingles, but I suspect this isn’t the case here. . . .
When I did the seismic bracing in my house I was required to use 5/8" plywood (that’s with studs 16" OC) and there were a lot of nails (I think it was 3" around the perimeter and 4" in the field for each sheet…I gave my framing gun a good workout). But that’s here in CA (earthquake country) and it was the house, not a standalone shed. A friend of mine who is a professional carpenter and homebuilder says that he’d never use OSB for sheathing, FWIW.
I’m definitely with others who have suggested 16" spacing and more rugged sheathing. Quarter inch masonite? Isn’t that pegboard without the holes?
Thanks for the seam advice - I hadn’t really considered it yet, but now I’ll draw that into my plan. It occurs to me that a bead of construction adhesive would help keep the plywood edges from getting out of joint too badly and help seal that joint against moisture.
That’s interesting. I’ve driven through a lot of subdivision projects in the last 6 years and it seems like OSB is routinely used to skin the frames of the houses being built, from low-end cookie-cutter builders to custom-home outfits. I recently read that OSB is considered a fairly strong material as long as it’s applied correctly. Did your friend give a particular reason for disliking OSB? Or is it just the necessity for meeting stronger seismic codes in your area?
A couple years ago I built a very small shed to house some tools and used OSB for the floor, roof, and wall panels. It’s done a good job surviving two Northern California winters, and I didn’t add any additional siding - just a coat of primer/sealer and some caulk along the seams. (I suspect it might not be as sound as I think, hence the new project. Plus, it was really small.)
Pegboard is usually a bit thinner, I believe.
FWIW, I gave him the :dubious: when I asked him today, but he assured me that’s what he used, and the building looks great and is quite sturdy.
My friend said that he’d seen the stuff come apart - this may have been because it was left exposed during construction and it got wet though.
http://www.toolbase.org/Technology-Inventory/Interior-Partitions-Ceilings/new-generation-osb - some info and a comment regarding delamination if it gets wet. This can certainly happen to plywood too, although I left a sheet of cheap 5/8" plywood sheathing outside for a couple of years and it was still remarkably sound when I finally broke it up for the trash - it was a bit warped but the only thing that would take it apart was a Sawzall; even when I cut some 1’ wide strips I could jump up and down on them and they just would not break.