DIY Home Improvement Forum banner

Shed floor system (deck)

1867 Views 9 Replies 6 Participants Last post by  Drachenfire
To make a long story as short as possible, I'm building a 8x10 freestanding deck on which I will install a metal garden shed. I'm figuring 2x6 PT joists, either new or recycled from a deck I'm taking apart.

Questions are: Is a double rim joist (band) required (as I've done in the past on decks) or single OK?

And for decking under the shed, plywood, T&G OSB, or used 5/4 boards?
The shed mfgr says no PT touching the metal. I'm thinking about putting foam sill plate gasket between the 5/4 boards and shed. Good idea?
1 - 10 of 10 Posts
We build floors and decks with 2x10 joists so no comment on 2x6.

Sill gasket should protect the aluminum from the copper treatment.
An 8' 2x6 is fine for the floor joists.... unless you plan to park a riding mower in there. I've built several sheds using 2x6s.
As far as the double rim joist vs. single, it depends on what it will have to support, how the rim will be supported (e.g. sitting on gravel the whole length, on supported by several posts, or just posts at each end), and the depth of the rim joist.
For a 8'x10' deck, 2x6 joists seem good enough.
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.
See less See more
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?
See less See more
Based on your anticipated use/loading, 2x6 joists should work fine.
If you don't anticipate the floor getting wet alot, the T&G OSB (5/8" or 3/4") should be fine. I used regular 7/16" OSB sheathing for my storage shed, and it doesn't have any noticeable give to it. I had to do my framing carefully so that the joints in the sheathing were on a joist, but it wasn't difficult.
Got it done. Ended up going 6'x8' for a smaller shed. The crazy thing was that the shed isn't really 6x8. The mfgr said to build a 68 "x 97.5" platform. WT??? Anyway, it came out nice. 2x6 joists, double rim joist at the front, under the door. Just two seams in the OSB floor. Sitting on deck blocks, with 4x4 posts to get it level.

Thanks for the help!
  • Like
Reactions: 2
Glad you got it built.
  • Like
Reactions: 1
1 - 10 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.