Foundation for non-load bearing exterior wall

[Llamas]

This is a question about the foundation for a wall, so it almost applies to this forum...

I'm looking to add a fourth wall to a three sided garage (don't ask, I didn't build it). The current walls support the roof and a room above the garage. There is a concrete stemwall foundation on one side and the back, and a large footing at the other corner. The opening is currently fully supported by the existing structure.

Will I need to dig and pour a stemwall to put in this wall, or is the garage's concrete slab sufficient? I guess I should be asking, is the stemwall required by code? If not, this is a straightforward project. If it is, it's going to hurt.

Thanks,

--Mike

[Rich]

Is the area in question exterior or interior? Is the wall load bearing?
I guess I need to know what the layout is to make an educated guess. Where in relation to existing walls is the new wall going to be? More information and I'm sure I can help you.

[Llamas]

Exterior wall, non-load bearing. The structure is a detached garage/carport, open on one side. Let me take a shot at some ASCII art:

Exterior walls on concrete stemwall on side and back
____________ <--
| |_Shop_ | /
| | | <--
|<-Garage|=|
| Door|=| <-- Stairs to second level
| |=|
O / _O
Footing Footing

There's currently an opening, about the same width as the double garage door, between the two footings. So, the second story of this structure is currently supported, as designed, with no load bearing wall in this gap. This gap is open to the outside, with a walkway between the structure and the house. The shop/utility area wraps around to underneath the stairs. The stairs are an interior feature accessed by a door.

It'll be a few days until I can get a picture...

[Rich]

Ok. Nice job on the artwork there :D
Kind of a strange layout but I understand what you're saying. I think it will be find placing the wall directly on the slab without a footer. One thing to make sure of is that the connection between the slab and framing be taken care of extra special of, for waterproofing. Also make sure bottom plate is pressure treated.

[Llamas]

It is an odd setup, and I want to close it off so I can use the garage as a shop. I may have to remove some interior, non-load-bearing walls where the small shop room is (another issue) to make room to push my tools back out of the way, but that's secondary to closing a 15 foot hole in the side of the building.

Since we will be doing other work on the house that we'll be permitting for, I'd prefer to just get a blanket permit to cover everything. I feel better going into this that I (probably) won't be told that I have to dig things out and pour a full stem wall.

Thanks,

--Mike

[Rich]

Let us know how it all turns out.

[Llamas]

We take possession in three weeks. I'll post follow-up info as I go.

Thanks again for the help.

--Mike