Enclosing garage, tips?

[mendozer]

So I'm about to start a project to enclose a carport and I wanted to double check a few things. Previous owners converted the old garage into laundry room and storage, then built out post and beam support for an open carport (so thick solid beam and beams with poured footings). The current "garage" pad is what was presumably the flat pad which was the old driveway. There's a clear division of newer concrete however which was likely the footing. My plan is to enclose walls and extend the pad a bit (it's not truely squared to the house).

I haven't dug under yet, but I'm planning to dig out underneath the current pad to inspect the integrity and possibly add a long foundation inline with where the future wall will be on the one side that's not square. When I look into footings, typical "T" shaped ones are seen, but that's to be under the foundation wall. I'm not making foundation walls for a house, Just a standard 2x4 framed wall with fiberboard siding to match the house. So....

A. make a form that extends current pad size to where it needs to be at same 4 inch thickness.
B. dig deeper than current pad inline with beam on top to make a wider footing (say 8 inches wide x 6 inches thick) and once that's set then extend the pad over this and place a wall over it.
C. Neither, both are stupid, I have a better idea. And it is....(please share)

Also, only one edge of the pad is available to dig under. The other abuts a walkway entry to the home and is rather set in place (slate slabs).
Since the carport construction is coded properly (assumed as it was a permitted renovation) then adding the walls isn't going to really add that much weight, maybe a few hundred pounds??

 

[matt_i]

I think your B is a good idea but make it deeper. Dig 6" wide (or a shovel width for that matter) x 18" deep. Just fill the earthen trench and you can form the top ~6" or so with wood to make it look nice.

I'd pound a couple of rebars into the ground at the bottom of the trench just so you can tie some horizontal bars to them, to keep everything aligned if it cracks. On that note I'd edge-drill the slab every 24" or so and put some rebar pegs in there to help tie the footing and floor together as you want them to stay aligned.

Lastly its much cheaper to set anchor bolts in wet concrete than drill & epoxy later, so some review of the framing plans are needed to select the best locations. Every wall section needs at least two, I think around 8" max from each end, and something like 4' max between bolts. My numbers on the anchor bolt locations are approximate, there are legit code numbers that I've obviously forgotten.

 

[jmarkwolf]

Do a search on this forum. You'll find good discussions from others that have done the same thing.

 

[mendozer]

Thanks Matt. I was planning on drilling into the current slab for tying into it, but wasn't sure until I dig away to see how thick it is. So the footing should come up to just below the "slab level" so the slab rests on it, but I'm trying to figure how the pegs will tie into the bottom of the slab and top of the footing. Do you leave rebar sticking out of the footing 2 inches to meet in the middle of the 4 inch slab?

 

[matt_i]

Not following 100% but keep rebar in the center of all concrete pours and you should be good. The existing slab is already cured so you'd have to edge-drill that.

 

[fourjeepin]

I enclosed mine. Not saying it is right, but I didn’t add a foundation as, like you mentioned, it is only adding non load bearing walls.

You didn’t mention it, but I would recommend building a short wall of block to build on top of. I didn’t and haven’t had any issues, but would if doing it again.

 

[mendozer]

I drew up a quick sketch here. Here you see the representation of the triangular void I need to make to "flush up" the square flooring, then the extended slab as a side walkway. The footing below is what I imagine a footing needs to be. I don't actually know. Can it just be a deep rectangular trench with rebar? For homes they're just posts going into big cylinders onto flat discs, at lease my last house was. these walls aren't "load bearing" in the sense that they will be installed to the floor and the thick beam running across the top of the carport. They will however "bear load" from wind, wall mounted cabinets, etc.

 

[sarah-j]

Of course, if you dig deeper and consider a new surface several times better than the first.
And of course, you have to keep the floor fully prepared for mistakes
In this case, I think rebar is the best use.
And of course, reading several articles from Homebuilders Custom can also be helpful.
To make the best changes.