Concrete slab foundation

[Sirgeo]

Hi all, total newbie here with zero masonry and little building experience, but high hopes to build a sweet backyard oven/countertop/grill combination for my pops. I have a questions regarding the concrete slab that will support the entire project:

Already in place is a 10'9 x 6' concrete slab that was poured about 10 yrs ago to hold a gas grill. It is 4 inches thick and NOT reinforced with anything. It still appears to be in great shape, no cracks or deterioration. Do I definitely need to break this up and repour thicker and reinforced? If need be I will, for sure, but if not totally necessary it would be great to have that head start. Any feedback would be really appreciated.

This is an awesome forum, very grateful I stumbled across it. Already learned so much from exploring it, but I still have so many questions that my head is spinning, so figured it start with step 1 (foundation) and go from there. Thanks all.

[SableSprings]

Welcome Sirgeo! My thought is that you'll find the 6' width more of an issue at this point (although knowing the base underlay of that slab would be a critical piece of information to answering your question). Is there any option to expand the slab? Many people find in doing the combination backyard cooking area, that an L shape can work very well. I don't know what the area around the slab is, but grass will get trampled and turn to mud pretty quick. Think about the cooking area as an entertainment center and how/where people would sit/stand/watch as well as your Dad's working/standing area in front of each cooking/prep area. Another thought is getting him one of the Forno Bravo kits (or pre-builts) and a metal stand that could be positioned pretty much on any portion of the existing slab...they are a lot lighter (and quicker to first pizza ) than building your own supporting foundation and brick oven. Just a thought...

I know that concrete has great compression strength on its own, but not a lot of strength in terms of lateral strength without the rebar. If you can expand the slab and plan for rebar under where the oven would be positioned, it would probably be a good way to go if you are determined to build the entire structure yourself. I'm certainly not a structural engineer, but I went with 4" and rebar under my primary den slab and 5.5-6" with rebar under the corner that the oven occupies. I'd hate to think of you breaking up the existing foundation if you could use it and simply add an extension for the oven area.

Relax about being a "total newbie" ... most of the folks here with successful builds started with exactly the same concerns, questions, and head spins. Make sure you take the time to consider the value of doing your own build vs buying the pre-fab modular oven kit or completed version. Hope this helps!

[Sirgeo]

Thanks for the response! Good idea, might consider doing that, pouring a reinforced extension under the oven, which will definitely be the heaviest part. Much appreciate.