# Floor joist size for garden shed?



## Artie2 (Jun 24, 2008)

I'm going to attempt to build a backyard shed. I don't really like any of the ones from the big home improvement stores. I have an idea for a quasi-modular design. Basically, I want to build 4x8 floor modules, then link them together, with either 2x10 or 2x12 side rails, with however many modules I want for the size floor.

My main question is, could I use 2x6's, or maybe even 2x4's for the floor joists, given that it's only an 8-ft span? Should I use 12" (fig 2), or 16" (fig 1) OC? For the side rails, could I use 2x10's, or would I need 2x12's?

Thanks all. Hopefully, my pics will show up.


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## Daniel Holzman (Mar 10, 2009)

The size depends on the load. The load depends on what you are putting in there. If you are storing gold bullion, you need a bigger joist than if you are storing styrofoam beads. What are you putting in there?


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## Artie2 (Jun 24, 2008)

Basically, it will be garage "junk". I'll build 24" shelves that come in from both sides, leaving 4' to walk down the middle. Most of the stuff will be in those plastic bins and will sit on the shelves. So not really any load on the floor. Then basic garden tools, weed-eater, etc. No garden tractor.


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## Nealtw (Jun 22, 2017)

You are trying to hard.
Modular is a waist of work and time. You want to use tongue and groove sheeting.
Adventech looks like OSB and you build it 8 by 12
Plywood is samller so you build it 95" by 12 ft
2x6 treated for floor framing is good bet. I would build the frame on the ground all 2x6
16" on center. One rim joist and the a 2x6 on flat to cover the 12 ft rim joist and the ends of the joist. then turn it over and st it on 6 concrete blocks the you buy at HD.
Make sure it is square by measure the angle from corner to corner both ways and you are ready fro sheeting. Treated deack screws for the treated wood.


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## 123pugsy (Oct 6, 2012)

x2 on the 2x6's.


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## mark sr (Jun 13, 2017)

If your land is like most of the fla 'sand' it would be best to either pour a footer or set some cap blocks under the blocks the shed will set on. While frost heave isn't a concern, settling in the sand is.


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## Colbyt (Jan 27, 2014)

Florida may have some 'tie down' restrictions for sheds. I imagine the coastal areas do for sure.

Agree 3 with 2x6 ok and build the floor on site.

These guys, http://www.homedepot.com/p/10-in-x-10-in-x-10-in-Concrete-Deck-Block-55N1AN/206125490 make it easy to level a shed on uneven ground.


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## Nealtw (Jun 22, 2017)

That might be a good place for those new deck blocks that are made with hole at 45* so you hammer in 4 length of steel pipe to lock them to the ground.

Saw post here the other day in a thread about decks.

Then you would still have to tie the shed to something.????????????


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## Drachenfire (Jun 6, 2017)

I built a 10x12 foot shed which is a full 8 feet at the walls.

It sites on 30 pier blocks which is on a 3-ton gravel base. 

The floor is made up of 2x6 PT rim joists along with 2x6 PT floor joists spaced 16 oc. 
This is covered with ¾ inch PT plywood. 

The walls are framed with 2x4 studs and sheathed in PT T-111 plywood. 

The roof is made up of homemade 2x4 trusses secured to the top plate with hurricane brackets and a 2x6 ridge board. It is sheathed in OSB and shingled to match the house. There is a 5’wx6.5h’ double door.

Inside there is a 4 foot wide loft at the back wall for storing small, lighter items.

Everything is held together using screw-shank nails. They are a little harder to drive but much more secure than common nails and cheaper than screws.

The shed was covered in 2 coats of primer sealer followed by 2 coats of exterior latex enamel colored to match the house.

In addition to the usual yard care implements, I store my riding mower, push mower, pressure washer, snow blower and dedicated curb edger. I have never had any issues with floor sagging, lifting or warping.

I have had the shed for almost 15 years and have only had to re-paint it once.


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## Artie2 (Jun 24, 2008)

Nealtw said:


> Modular is a *waist* of work and time.


Freudian slip? My wife says I need to find the time to work on my waist. :biggrin2:

Seriously though, I retired earlier this year, so I have all the time in the world. Also, since I now have the time to mess around in my shop, and dust off the old tools, I'm not sure I'd call it work. And, I tend to think outside the box. 

On the other hand, I don't want to do anything silly or wasteful. I'll rethink my "modular" idea and check out all your ideas. I was hoping to use those pier blocks that have the 4x4 indentation in the top and the 2x cross-hatch pattern. I definitely need to anchor this down due to our occasional high winds. 

Thanks for everyone's comments and ideas. I guess I still have some more planning to do.

P.S. Part of the reasoning behind my modular design, was that I could construct the modules in my shop, at my leisure, and then when ready, carry them outside to assemble. If it rains while I'm constructing them . . . no problem.

Artie


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## Nealtw (Jun 22, 2017)

Artie2 said:


> Freudian slip? My wife says I need to find the time to work on my waist. :biggrin2:
> 
> Seriously though, I retired earlier this year, so I have all the time in the world. Also, since I now have the time to mess around in my shop, and dust off the old tools, I'm not sure I'd call it work. And, I tend to think outside the box.
> 
> ...


Some people spell good and some people build houses.:vs_cool:

Dig a hole for concrete to anchor the shed
Use a sono tube just for the top foot in the ground and a few inches above ground and install saddles and and set what ever you like in them to support the floor.
https://www.homedepot.ca/en/home/p....498809983872&gclid=CL-Krv6uhtUCFc6XfgodbgUPnQ


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## Artie2 (Jun 24, 2008)

Thanks Neal. That sounds like a plan. And yes, I are a good speller. 

P.S. Are you saying I only need to go 12" deep on my concrete?


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## Nealtw (Jun 22, 2017)

Artie2 said:


> Thanks Neal. That sounds like a plan. And yes, I are a good speller.
> 
> P.S. Are you saying I only need to go 12" deep on my concrete?


No. some people dig a hole and put the tube to the bottom and then back fill and end up with a leaning pier. fill the hole with concrete and use the tube to form what comes out of the ground and everything is solid.
You want to make sure the tops are level, although you can wedge thing up later if you screw that up.


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## Artie2 (Jun 24, 2008)

Got it. Thanks.


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## NotyeruncleBob (Mar 9, 2017)

Artie2 said:


> I'm going to attempt to build a backyard shed.


No. You _will_ build a backyard shed. There is no attempting.



Artie2 said:


> I don't really like any of the ones from the big home improvement stores.


Amen! You can build something much better for less money. 



Artie2 said:


> I have an idea for a quasi-modular design. Basically, I want to build 4x8 floor modules, then link them together...


Nah, that's not really a good way to do this. Linking the "modules" will be a PITA and it won't be as strong as stick building on the ground. 



Artie2 said:


> My main question is, could I use 2x6's, or maybe even 2x4's for the floor joists, given that it's only an 8-ft span?


As long as you're not parking a riding lawn mower on it, then yeah 2x6 is the minimum...but you should provide a little more support in the middle if possible. You can bridge the joists at the middle by nailing in 2x6 blocks between joists. Make these snug and they'll help to distribute the load from one joist to the ones on either side. You can also put in a couple blocks in the middle of the joists to keep them supported.


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## BIG Johnson (Apr 9, 2017)

Drachenfire said:


> I built a 10x12 foot shed which is a full 8 feet at the walls.
> 
> It sites on 30 pier blocks which is on a 3-ton gravel base.
> 
> ...




Wouldn't a concrete floor with some anchor bolts have been easier?


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## Artie2 (Jun 24, 2008)

NotyeruncleBob said:


> As long as you're not parking a riding lawn mower on it, then yeah 2x6 is the minimum...but you should provide a little more support in the middle if possible. You can bridge the joists at the middle by nailing in 2x6 blocks between joists. Make these snug and they'll help to distribute the load from one joist to the ones on either side. You can also put in a couple blocks in the middle of the joists to keep them supported.


By "blocks", do you mean this? (The gray parts.)


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## NotyeruncleBob (Mar 9, 2017)

Artie2 said:


> By "blocks", do you mean this? (The gray parts.)


yep. 




12345


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## Artie2 (Jun 24, 2008)

Is the "12345" a clue?


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## NotyeruncleBob (Mar 9, 2017)

Artie2 said:


> Is the "12345" a clue?


No, this site doesn't let you post a reply shorter than 5 characters. First thing I could think of to take up the space.


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## Artie2 (Jun 24, 2008)

That's interesting. I'd think a DIY forum would like the idea of succinctness. 

Wow! That was too many words to say O-tay!


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## Drachenfire (Jun 6, 2017)

BIG Johnson said:


> Wouldn't a concrete floor with some anchor bolts have been easier?


Not for me.

Pouring a slab would have required a construction permit and inspectors. The cost of grading, forms, steel mesh and rebar would have doubled the cost of the shed and time it took to build.

The way I did it only required a zoning permit and no inspectors.

I had the three tons of gravel delivered on a Friday but the driver would not back the truck to the shed site as the ground was wet and he was afraid of getting stuck. I had him dump it in the driveway from which I moved it by wheelbarrow to the shed site. 

I moved the gravel, leveled it, laid and aligned the pier blocks and installed the flooring in a weekend.

It would have probably taken me 3-4 weekends minimal to do a slab weather permitting.


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## BIG Johnson (Apr 9, 2017)

Drachenfire said:


> Not for me.
> 
> Pouring a slab would have required a construction permit and inspectors. The cost of grading, forms, steel mesh and rebar would have doubled the cost of the shed and time it took to build.
> 
> ...



I did a 12x16 shed last summer, paid my concrete guy $200 cash + concrete. Had him pour thicker around the edge and embed anchor bolts. Whole shed cost about $2K. Only a zoning permit required under 200 sq ft..

I did have to bring in a few pickup loads of sand to level the area but there's a nursery almost next door and I used one of those bed unloaders from harbor freight. All those costs are included in the $2K.


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## Drachenfire (Jun 6, 2017)

BIG Johnson said:


> I did a 12x16 shed last summer, paid my concrete guy $200 cash + concrete. Had him pour thicker around the edge and embed anchor bolts. Whole shed cost about $2K. Only a zoning permit required under 200 sq ft..
> 
> I did have to bring in a few pickup loads of sand to level the area but there's a nursery almost next door and I used one of those bed unloaders from harbor freight. All those costs are included in the $2K.


We all do what works for us.


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