Expanding a slab

[Crocodile Tears]

So, I've got an annoying scenario that I'm trying to game out.

My house has a small detached 12wide x 16deep basic garage out back on a concrete slab. Its in mediocre shape, but I feel could be saved. The garage sits directly on the property line with the neighbors. It is also located on an alley, which sits up above grade. Thus, over the years, water intrusion has been rotting out the garage door itself, and the slab gets wet easily.

The size works.... ok. I'd like to expand another couple feet into my property, turning it into a 16w x 16d, retaining the existing wall. I am limited in depth, as one of the better trees on the property is pretty much directly behind it.

The garage only really needs to handle motorcycles and my basic lawn equipment. If I go through with this, I will add electrical.

I guess I'm looking for some opinions on what my options might be. Due to the alley nearby, along with the neighbor right there, I cant see digging out a drainage out front as feasible.

My thoughts went two different ways -

a) lift the garage a course of cinderblocks on the existing pad. Pour inside this to create a fresh lifted slab, plop the garage back down on top, and create a ramp of some sort to even out the alley entrance. If I decided to expand the slab the four or so feet into my property, do site work inside my land and place fill material, then utilizing the same concept fill a cinderblock perimeter to even everything out.

or

b) I dont necessarily need a slab - I dont plan on using it for vehicles due to the depth limitation, so, tear it down, put down piers for the expansion, and build a wood framed floor that has close enough spacing to support a couple bikes and some lawn equipment. Then construct my 16x16 or so shed on this treated floor. Most of it would sit on the existing slab, though the grade issue would not be solved. A ramp of some sort would be utilized for entry.

In both of these plans, I'd like to replace the man door with a double door so pulling lawn equipment through for use would be easier. Because of the rotted garage door and the amount of rework needed on the existing frame, I think it makes most sense to try to just build from scratch.

I can take some photos of the scenario later if it helps anyone. Construction isn't really my thing, I'm more of an electrical guy. Any thoughts would be appreciated.

Thanks

 

[astroracer]

The 1st thing you need to do is check your local codes because you will need to know if removing the old shed will require the new one to adhere to any set-back rules.
Once you figure that out, for what you would need to put into the shed to "save" it I would look into a pre-built unit. Don't know where you are located but, around here, the Amish have some very nice pre-builts for very good prices. Rip out the old shed (or sell it...) and drop in a new one.

Mark

 

[Jeff Ivers]

You don't say how much higher the alley is than the floor of the garage. Why not just jack it up enough to form up for a 3.5 inch slab poor directly on existing floor regardless of whether you expand width or not? The only advantage I see of raising and setting on block is you can lower it onto the block and remove jacking support before pouring. The disadvantage is perhaps higher than desired (requiring ramp) and needing to fill the block to the slab thickness.

 

[Crocodile Tears]

You don't say how much higher the alley is than the floor of the garage. Why not just jack it up enough to form up for a 3.5 inch slab poor directly on existing floor regardless of whether you expand width or not? The only advantage I see of raising and setting on block is you can lower it onto the block and remove jacking support before pouring. The disadvantage is perhaps higher than desired (requiring ramp) and needing to fill the block to the slab thickness.

I suppose my reasoning with the block was to not have to set up forms infringing into the neighbors yard. Kind of a different way to skin the same cat.

I haven't taken exact measurements, but I believe 6" minimum is where I'm going to stand, so the block seemed a good unit of measure to use.


Correct about needing to research the codes, of course. I just want to have a somewhat sorted idea before I go in and start spewing nonsensical gibberish at the inspector. Due dilligence up front.

We're not too far from some pretty decent quality amish shed build sources here in NW Ohio. My preference is to do it right and retain a true garage on the property, but the shed is a solid alternative that works for me. For whomever owns the place next (I don't see this as a forever home), the true garage likely maximizes value at sale.

 

[Leaflessshadetree]

If you are allowed to completely rebuild the structure that close to the propertyline it will be very difficult to do without being on the neighbors side occasionally. Putting in forms would require it less than laying block. Forms can be built and removed working only from the slab side.
If you pour larger than the existing slab it is almost certain to crack above the edge of the old slab. I'd recommend busting it all out, fill, compact set the forms at teh desired floor level and pour the new slab.

 

[SGKent]

better define what you expect from your new garage than how to build it. Your first post is more what you don't want with the old one than what you do want with your new one. Then you can start looking at how, codes and cost, etc..

 

[NUTTSGT]

Check with your AHJ first and foremost before you plan anything. No reason to get started when you are going to have issues.

 

[rayra]

You don't say how much higher the alley is than the floor of the garage. Why not just jack it up enough to form up for a 3.5 inch slab poor directly on existing floor regardless of whether you expand width or not? The only advantage I see of raising and setting on block is you can lower it onto the block and remove jacking support before pouring. The disadvantage is perhaps higher than desired (requiring ramp) and needing to fill the block to the slab thickness.

This is the answer.
There's lots of ways to beat any code restrictions and keep costs reasonable.