Galvanized Base Shed

[Boudin]

I have an existing 12x24 shed with a galvanized steel base and plywood floor. It's joists are 24" spaced with concrete blocks and wood leveling wedges in some spots. Load rating is 50psf.



I want it on a concrete foundation but not sure how I should approach it. What are your thoughts on cutting the wood floor out, forming around the shed and pouring concrete as it sits? I imagine that would give me the concrete floor I want but wouldn't actually be load bearing to the shed itself as it's still on blocks that are now encapsulated in concrete.

Any other ideas? If I had to move it I don't see how I could as there are no skids and I think the steel frame would buckle if I lift or drag it. This is preventing me from selling it and starting over also.

Appreciate any input.

 

[kaymccampbell]

Coupla questions.
You want an actual concrete slab to walk on?
What's the shed frame made of?
What are the floor joists made of?
I'm sure there'll be more questions.

 

[AC-WC]

It looks like it was built off site and moved there i.e. it can be picked up and moved. I don't think I would cut out the floor and pour inside. I think it would weaken your overall structure. Pretend it's a cardboard box. Cut out the bottom and see how strong this is. This is different than a traditional stick build or pole barn structure.
Have you YouTubed moving large shed? There's some really cool tools out there but not sure where you could rent them.

 

[readhead]

What is your ultimate goal? As you mentioned you can’t move it because of the flimsy metal floor system. We have come up with a system to move Tuff sheds but it is involved and rather expensive. Generally I turn down requests to move Tuff sheds but some people insist because they have built out the inside and don’t want to let it go.

If you want a slab you can jack it up, support it with some beams attached to the walls, cut the floor system out completely, pour a slab, drop it back down and attach the walls to the slab. A little time consuming but doable.

 

[readhead]

To answer Kay’s questions, Tuff Shed builds on site. The floor system is made up of light gage sheet metal including the rim and joists. It is supported by bricks placed under the rim and joists. It is sheeted with 3/4” t&g OSB. The building is framed on top of the floor.

While most sheds are built on pressure treated skids with wood joists TS started pushing the metal floor system years ago convincing customers that it is a rot resistant superior product. Maybe so but besides being almost impossible to move, when I was a dealer I dealt with several floor problems. Strangely enough you can buy a Tuff shed with a wood floor system and skids but you have to know how to ask for it.

 

[Boudin]

What is your ultimate goal? As you mentioned you can’t move it because of the flimsy metal floor system. We have come up with a system to move Tuff sheds but it is involved and rather expensive. Generally I turn down requests to move Tuff sheds but some people insist because they have built out the inside and don’t want to let it go.

If you want a slab you can jack it up, support it with some beams attached to the walls, cut the floor system out completely, pour a slab, drop it back down and attach the walls to the slab. A little time consuming but doable.

To increase the load capacity of the flooring so I can install a scissor lift, and store heavy machinery (lathe, press, milling machine, engines etc). How are you installing/attaching the beams to the walls? How many bottle jacks per side do you think I would need?

Coupla questions.
You want an actual concrete slab to walk on?
What's the shed frame made of?
What are the floor joists made of?
I'm sure there'll be more questions.

Yes
It's 2x4 framed
Floor joists are galvanized steel every 24"s

 

[readhead]

I would attach a double 11 7/8” LVL on each side about two feet above the floor and extended at least two feet past the end wall. A five ton jack at each corner and cribbing to replace the jacks once it is up at least a foot. The walls are attached with #14 tek screws. You should be able to remove the screws and the floor will drop down. Excavate for the concrete, plumb down from the corners, place the forms, pour the concrete and drop the building back down.

 

[mike93lx]

without properly prepping the base for concrete, you will likely get cracking.

i think i'd consider moving it, prep and pour the pad, brace up the interior, cut the walls from the floor with a sawzall and then move it onto the new slab.

 

[readhead]

No reason to move it. There is plenty of access to prep the slab because the floor is gone. Plus there is a good chance that the building is not square. Having the building right there means you can plumb down from the corners and get the forms perfect to fit the building.

 

[mike93lx]

No reason to move it. There is plenty of access to prep the slab because the floor is gone. Plus there is a good chance that the building is not square. Having the building right there means you can plumb down from the corners and get the forms perfect to fit the building.

The cross members are gone?

Working around 24OC framing sounds like tons of extra work, plus a recipe for poor prep

 

[readhead]

The complete floor system is gone. I should have mentioned that a few diagonal braces will need to be installed inside but they will not be in the way. This request comes up more often than you might think in the shed business. This is how new slabs are installed under existing homes but I’m guessing that most here have never been involved with the process.

 

[Boudin]

The complete floor system is gone. I should have mentioned that a few diagonal braces will need to be installed inside but they will not be in the way. This request comes up more often than you might think in the shed business. This is how new slabs are installed under existing homes but I’m guessing that most here have never been involved with the process.

Your information has been very valuable. I'm thinking this is the way I'll be moving forward. Internal bracing noted. Run the LVLs run along the 24ft walls and not the 12 ft ends, or both and intersect at corners?

What hardware do you use to attach the beam to the walls? Lags through every stud?

 

[readhead]

I would use GRK or timber teks every other stud. They leave a smaller hole than a lag. Both sides is enough but you can run them across the ends as well. You will need to tie the walls together where the doors are. We usually remove the doors for easier access. The reason why we use LVL is you can can get them any length up to sixty feet. You can also sell them after you are done.