My house is two stories on a slab in Pennsylvania. My house is L-shaped. I am putting on an addition of a 14' by 14' room on the second floor and a bathroom that is 14' by 5 1/2' on the first floor (the bathroom is smaller due to a previous kitchen addition on the 1st floor). I jack hammered and removed the side concrete porch where the bathroom will be placed. I have dug out (by hand) a 3 foot deep by 18 inch wide trench on the outside edge of that space. The drains for the bathroom will be put in Monday. I want to setup to pour the foundation in the trench and a 4 inch slab which will be connected to the existing foundation - I believe that is called a mono-slab. I intend to drill into the existing foundation and cement in rebar above grade to connect to the new foundation. Also I plan to use wire mats in the 4" slab and wire tie that to the rebar connected to the existing foundation and the rebar in the new foundation/trench. My question is, how exactly how to place the rebar in the trench to prepare for the pour? I intend to use 1/2" / #4 rebar placed on 2" by 2" wire dobie concrete bricks. I was thinking that I would create 12" wide by about 32" tall squares and place them vertically every 2 - 3 feet on the dobie bricks, and these squares would also tie onto the wire mat. I would then tie 2 horizontal runs at 1' and 2 horizontal runs at 2 1/2'. I attached a picture of my house and my plan for the rebar placement. Please let me know if you feel my plan will work or if there is a better way. Thanks for your help.