Shed Foundation Questions.

[poconosms1]

Hi All,

I'm planning on constructing either a 12x16 or 12x18 shed. I've been torn between pouring a 4 inch foundation or constructing on a foundation of stone.

My understanding is that if I use a stone foundation, i'll need to construct the shed floor on skids. I have a couple of questions.

I have a garden tractor, which when combined with all the attachments that I'll store in the shed, have a combined weight of approximately 1200 pounds. Add to that a heavy duty snow blower. the tractor is 1,000lbs with the front bucket attached (Johnny Jr)

If I run the floor joists the 12 foot run, should I use 2x6 or 2x8? I was thinking of doubling the joists in the middle, which is where the tractor would be parked.

If the skids are pressure treated, which I was thinking of staining, should the floor joists also be pressure treated? I would stain these as well.

If I construct the 12x18 shed, the rear will be approximately 10 inches from a tree. The wife doesn't want me to take it down. the Tree splits at the base into two off shoots (like a Y). Each off shoot is about 6 -7 inches diameter. Both branches lean away from my proposed shed, so there is no chance of the tree ever falling on the shed. I can't move the shed forward because the front would end up in the driveway. Does anyone see a problem with this?

 

[Notgrownup]

4" slab would be way more solid. Some footers on the edge 12x12 in dimension, rebar if you are in a colder climate...if framed use treated skids and treated 2x6 12" on center... 1" plywood should support the tractor fine.
What region are you in.

 

[rburke65]

You will never regret building the shed a little bit stronger, a little bit better than you need. 2x6 vs the 2x8's go with the 8s. Go with the concrete floor you won't be sorry. Good luck.

 

[kelpaso1]

You will never regret building the shed a little bit stronger, a little bit better than you need. 2x6 vs the 2x8's go with the 8s. Go with the concrete floor you won't be sorry. Good luck.

Well if he goes with a concrete slab then there would be no use for floor joists

 

[scootermcrad]

I would go with a slab, if your grade allows for it. Otherwise, several 12" columns and the structure to support it. If you do a framed "skid" construction, make sure the floor joists are running a direction that makes sense for how you're driving the tractor in and plenty of floor sheathing.

I'm just finishing up a 12x16 shed for all my lawn equipment, zero turn, push mower, etc. etc. and I went with a framed construction instead of a slab because of the grade. But my zero turn is the heaviest thing going in there and it weighs half what your machine does. Here's the 12x16 I'm finishing. Maybe something will help you in the post...
http://www.garagejournal.com/forum/showthread.php?t=256656

One other thing, make sure if you plan out a 12x18 shed it makes sense from a materials stand point.

 

[brass89]

Only thing I can see maybe is the tree. 10" isn't a whole lot of clearance, any chance the shed could move just a little further from the tree? Reason I say this, I had a tree like the one you're describing - matter of fact a crew just took it down about 20min ago. I don't know how old your tree is, it may be fine for years yet. Mine eventually died and split right down through the crotch (the "Y") to the point the tree crew had to tie them and draw them back together just to brace them enough to cut them down. 10" doesn't leave much space and certainly not if it's on a permanent slab.

Not trying to scare you, just thought I'd mention it especially since I just dealt with a similar issue you might face in the future. They had a time of it and that was without a building butted right up to it.

 

[volleyball]

I don't get the 12' span. Put a bunch of supports under there, double up the 3/4" PT plywood floor and you'll be fine if you go wood.
What construction affects your property value? And does it matter? A concrete base may bring on a lot more expense than it is worth.

 

[poconosms1]

Thanks for all the great comments

 

[poconosms1]

that was impressive craftsmanship