Shed floor system (deck)

My 10x12 foot freestanding shed floor is built on 2x8 PT joists. I store all my lawn and yard equipment in there including the riding mower, snow blower and pressure washer along with miscellaneous other stuff like the 300lbs of sand bags I use in my truck when it snows heavy. There is absolutely no sag in the floor whatsoever.



How much weight you anticipate putting on the floor is a major factor in determining joist thickness and support.

I'm building this shed for short term storage of camping equipment, tools, and misc stuff while I rebuild my larger (12x24) outbuilding. After the new building is done (a week or so), the metal shed will contain an electric tiller, weed eater, maybe a push lawnmower, and an assortment of rakes, shovels, saws, etc. Garden shed stuff. Nothing big or heavy.

My existing building has a 4 year old deck on the front. I'm thinking about removing it and using the wood to build the floor system of the little shed. It's on a slope, so the floor joists of the shed will be on short 4x4's or blocks, about 6-8" off the ground in the front and 12-24" off the ground in the rear. Just high enough in the front to get it clear of the ground.

Based on the performance of the deck I'm removing, I'm pretty confident in using 8' 6x6 joists. I'm figuring the short sides supported at the corners, with a support in the middle of the 10' front and back.

For decking the floor, I could use the existing 5/4 boards. But I'd have to put the sill gasket between the PT and metal frame. Or I could buy new. What do you think of T&G OSB for the floor? Or spend more $$ and get plywood?