I don't see a problem with just building it out of 2x3s, Treated sill plates are fine but add a sill gasket too. .

 

I never built one and making some guesses. Less area for nailing, easier to split the ends with nails, more stud bending when standing the wall, esp if sheathed first, corners that much weaker.

These are just some suggestions. Use 12" spacing. Make the walls 7' high. Make in 10' sections, sheathe top 8', bottom 4. Single top plate. Stand, add 2nd top plate, overlapping the joint, then fill the middle sheathing.
There are light duty sheds with 2x3 but they are small. I think 2x3 studs will work for sheds your size but I'd worry about every joint staying tight until everything is stood and braced. I may use 2x4 bottom and top plates and definitely collar ties to keep the walls from spreading out.
If concrete slab, 2x3 wall's anchor bolts would get you closer to the concrete edge and more chance of breaking the edge. I may want to anchor the 2x4 first then stand 2x3 wall on top.

 

In my original post I did not correctly state what i meant by doubling the 2x3 up and i got the dimensions wrong of the doubled up boards. What i was meaning was to use 2 of the 2x3 to make a L shape. I believe it is called a strongback stud when you do it this way.

I do plan on using pressure treated 2x4 for the bottom and top plates and to use collar ties. I'm not sure if I need a building permit as i live in a small town in a rural area but i will be finding out before i purchase or build anything.

This would be my first attempt at building anything like this but paying someone else to do it just doesn't sit right with me. Between YouTube and forums like this hopefully I will be able to make a decent shed. Thank you all for the advice!

 

I'm with Neal....

I don't see material/significant issues given your specs and uses.

(I suppose you can make a shed out of grass or bamboo. Heck, they make them out of plastic.)

 

Single wide mobile homes are built with 2x3s. Don't see any reason why you can't do the same.

 

The better mobile homes use regular 2x4s on the exterior walls, interior walls are a different story.


IMO 2x3s are fine for shed walls, especially the non load bearing walls.

 

All of the prefab wood sheds I see are built with 2x3 walls 24"oc.

No need to double them up.

 

I'm in the early stages of planning out a shed. I have access to free 2"x3"x10' boards at work. I've been looking around and all i can find are posts about 2x3 vs 2x4 for framing. Most say that using 2x3 is not worth the small savings vs using the strength added by using 2x4. My question is could i double up the 2x3 and have a 4x6? Or even every other stud double it up. I do not plan on finishing the interior wall. The shed will not have electricity or plumbing of any kind. I was thinking The shed would be 10'x20' on a concrete pad. I will be buying treated lumber for any wood that touches the concrete. I haven't bought anything for this project yet fyi.
If it was me I’d frame the 20’ walls with 2x4 and the 10’ with 2x3. Not knowing factors like wall height etc. My advice is 2x3 studs under 8’ on a shed are ok. If you plate the 20’ walls with 2x3 the top plate will be to weak to lift.
If you have enough free 2x3 (and your really cheap) you could plate the walls 2x4 and use double 2x3 stud one flush with inside of wall and the other flush with outside) 24” or 19.2” o.c.
You can find sheathing rated for 24”o.c. Hopefully you know all the other effects 2.5” deep walls will have like R-value , 4-9/16 door jamb will stick out etc....

 

"Free Lumber" ?
Take it.
I've built more sheds with 2x3s than 2x4s.
No double studs needed, and brace the walls.

 

If using 2 x 3's can you still make it 16 inch centre or should they be less like 12 inch centre?

 

16" centers should be fine although it depends somewhat on the load the wall would be expected to carry.

 

Single 2x3 studs at 12" or 16" are fine for a shed with wall heights at least up to 8'; at that height, it might get some flexing in strong winds - I wouldn't try to drywall it. I wouldn't use it as a shelter during a tornado, either, but aside from that, it shouldn't be an issue.

The vertical load from the roof isn't anything to worry about - the axial capacity (along the stud length) is more than enough for the roof, with heavy snow loads, etc. Residential construction stud sizes are based on the vertical span (the height) and the resulting bending due to wind load on the walls (and sometimes just for space for more insulation), not for vertical load-carrying capacity.

 

You'll probably be fine. But I must say that in over 30 years of construction and remodeling I've never used purchased or used a 2 x 3 nor have I run into them on job sites. But if you can get them for free I say go for it.

 

I must say that in over 30 years of construction and remodeling I've never used purchased or used a 2 x 3 nor have I run into them on job sites. But if you can get them for free I say go for it.

I use them all the time in remodeling work and some for construction of storage sheds, and a chicken coop recently. The only reason I didn't use them more for the storage sheds, is that around here 8' is the longest that are available, and the sheds were more than 8' wide and deep. I built 2 storage sheds that were between 9' and 10' in both directions, and they were each under $400. The siding and roofing were free, but still I think I did pretty well.