Originally Posted by halestorm418
Just like mowerman says,
Use 3/4" 4x8 T&G Marine Ply with 2 x 12 Joists at 12"oc and you can park your car or a Sherman Tank in the shed. Yeh, also pour a perimeter 8" stemwall foundation to keep the water out.
Or you can save bucks and let the floor sag a little for a shed that will have less than a sunshine load on it. This is California sheds that last 50 years. I did not mention that an
8 ft span 2x8 DF joist at 12" oc is good enough to support an ATV. I have one and the
1/2" OSB holds fine, its the joist span sizing that will sag if there is no midspan support.
So sizing depends on what you plan to do with the shed. If it is going to be used for a cabin then I agree, use at least 5/8 T&G flooring if over 12" joist centers. Pier and posting is all that is needed for a girder system on hardpan poured pier pads. For a shed use a perimeter rim joist belly band in shear with posts to piers with a midspan girder on posts to piers. This is basic pole house structure design that works in high water table areas with posting going deep enough to hardpan.
No sense in spending a ton of money just to keep a lawn mower parked in a shed. If this is being done under permit, then this is a whole different ball game. I won't go there. Good Luck, nm