Shed on existing concrete slab

[veedublin]

I've got an existing 6'x12' concrete slab next to my house that's just screaming for a shed to be placed upon it.

I'm actually building a much more aesthetically pleasing workshop/poolhouse on the property, and I'll toss some pics up in the gallery. (That one is bigger, but still only 14x16 -- a mere child compared to the monster garages you folks are building.)

THIS little shed, probably a lean-to kinda deal will be nestled in next to the house. I'm not going to attach it to the house, so I don't need a permit for it. (Only 72 square feet.) I'm probably going to make the roof mimic the slope of the existing roof, hopefully making it blend in as much as possible.

The plan is to use this shed for easy access to bikes in the summer, and my snowblower and shovels and whatnot in the winter. (Our attached garage is a pitiful 20x20, so we can barely get our two small cars in it. And when the kids -- or me -- get our bikes out, it's a balancing act to keep from scratching up the cars.) Depending on space, I might use it to work on the bikes (minor repairs using a bike work stand, etc...), but it's not gonna be a workshop where I need comfort or a workbench or anything.

Anyway, for the existing-concrete slab, what would you do for the shed foundation?

Would you build a foundation frame (treated 2x4's?), and then build the walls on that? (And then you'd have a plywood floor 4" off the ground.)

Or would you just anchor the treated baseplate boards directly to the concrete? (And then you'd just have a concrete floor.)

 

[merc66rkm]

I would build the shed on treated joists, 4x4s would probably be fine. Attach plywood to that and then your walls on top. If you ever have to move it, it would be easy to do.
With just a 20x20 garage, I would build as big of a shed as you can, even if that means extending that concrete pad. Also, be sure to route your gutter downspout away from your new shed. Good luck.

 

[veedublin]

I would build the shed on treated joists, 4x4s would probably be fine. Attach plywood to that and then your walls on top. If you ever have to move it, it would be easy to do.
With just a 20x20 garage, I would build as big of a shed as you can, even if that means extending that concrete pad. Also, be sure to route your gutter downspout away from your new shed. Good luck.

Thanks, yeah, the downspout actually goes into a drain, which exits near the bottom of the hill on the other side of the yard.

4x4's. Yeah, that would be nice and solid, but still moveable. That will help when it comes to installing and painting siding on the sides nearest the house.

We're thinking of adding more concrete, like as a sidewalk, along the house, so that pad will be extended. (But I was thinking I'd like to keep the shed equal to perimeter of the house.)

 

[TractorJeff]

You build a shed without attaching it to your house, I would almost guarantee you'll have water intrusion issues! Water that right now can run away from your house will be forced to sit down along those walls and SLOWLY drain away giving it time to find an easier path(into house)

 

[PWC Repair]

By the looks of those downspouts, you'll have some pretty good runoff across that slab during a rain. I think I would build up on treated 4x6's as a portable building, run them with the direction of the runoff, and also notch out the bottoms of the 4x6's so any water on the slab finds it way out efficiently. You could also then easily move it later if you decide it's not working out and sell it.