[Zulu Kono]

I was planning on using this. Or whatever equivalent the lumber yard has.

https://www.lowes.com/pd/AdvanTech-Flooring-23-32-CAT-PS2-10-Tongue-and-Groove-OSB-Subfloor-Application-as-4-x-8/50126556

Is that sufficient?

Not for me it wouldn't be.
For shed floors I always use 3/4" pressure treated plywood.
It's green like the old Wolmanized pressure treated lumber.
No way would I use an OSB product on a shed floor.
And if the T&G part is where you're hung up, you can add
pressure treated 2x4 blocking every 48" between your pressure
treated joist material to keep edges of the plywood from deflecting.

 

[ACobra289]

Not for me it wouldn't be.
For shed floors I always use 3/4" pressure treated plywood.
It's green like the old Wolmanized pressure treated lumber.
No way would I use an OSB product on a shed floor.
And if the T&G part is where you're hung up, you can add
pressure treated 2x4 blocking every 48" between your pressure
treated joist material to keep edges of the plywood from deflecting.

I appreciate the info. I'm fine not using T&G, I just thought it was preferred for flooring.

I'm a little confused about the 2x4 blocking. My plan was to use 2x10 blocking down the center. (Approx 72" from each edge) Should I double up on that and put 2 rows of blocking? 48" from each side.

 

[House Designer]

I appreciate the info. I'm fine not using T&G, I just thought it was preferred for flooring.

I'm a little confused about the 2x4 blocking. My plan was to use 2x10 blocking down the center. (Approx 72" from each edge) Should I double up on that and put 2 rows of blocking? 48" from each side.

The blocking should be positioned to end up beneath any "free" edges of the plywood, since if it is not T&G then the free edges could deflect.

 

[Zulu Kono]

I appreciate the info. I'm fine not using T&G, I just thought it was preferred for flooring.

I'm a little confused about the 2x4 blocking. My plan was to use 2x10 blocking down the center. (Approx 72" from each edge) Should I double up on that and put 2 rows of blocking? 48" from each side.

One row down the center would probably be good enough.
The only reason to put it anywhere else would be to support the long edges
of the plywood between the joists so it doesn't deflect when you step on it.
If you wanted to do that, then yes, the centers of the blocks
should be 48" and 96" from the starting edge of the rim joist.
If your floor framing is exactly 12' wide, it should end up symmetrical.
I personally would do it because I hate the squishy feeling of a
deflecting floor board, but on a shed it's probably not necessary.
Concerning why I said 2x4, in these situations I put the blocking in flat,
i.e. the longer dimension of the lumber face up so I have more surface
area to land the plywood on, but if you wanted to put it in standing up,
you could even use 2x8 (cheaper) instead of 2x10, and block placement is more
important if you do that because you only have 3/4" to land your plywood on.
I'm going to emphasize this one more time:
Every piece of lumber in your shed floor system should be pressure treated.

 

[ACobra289]

I was always planning to use ground contact PT wood for the 6x6s and the floor frame/joists. Now, I'll be sure to use PT plywood for the floor as well.

Thanks for everyone's help and suggestions. I want this to be a solid shed that will last a long time.

I'm sure I'll have some more questions as I get ready to start building.

Thanks again.

 

[Nealtw]

I was always planning to use ground contact PT wood for the 6x6s and the floor frame/joists. Now, I'll be sure to use PT plywood for the floor as well.

Thanks for everyone's help and suggestions. I want this to be a solid shed that will last a long time.

I'm sure I'll have some more questions as I get ready to start building.

Thanks again.

Move up to 3/4" plywood as it won't have tongue and groove and with less the 3/4 you would have to put blocking under the join just to replace the T&G