The Office Floor

I need to figure out how I'm going to raise up this floor. It's a 3'6" x 9' x 3.5" space (roughly). In the picture on the left, I am raising up the floor from the front corner to the back corner. Fortunately, I don't have to cut any tiles because the joints fall exactly where I need to raise the floor.

from one direction

from the other direction

First off, I know I have to remove the saltillo tiles. Under the tiles, there are a lot of question marks!

Here's what I'm trying to figure out:
1. Can I pour a 3 1/2" layer of concrete on top of the concrete slab?
2. Do I need to drill holes into the existing slab and put short, vertical rebar?
3. Do I need to put a wire mesh/grid down?
4. Do I need to put some form of bonding agent on the existing slab?
and a few more questions, with pictures...

Regarding tying into the side of the house,


5. do I need to put horizontal rebar here?
6. Should I put an expansion joint between the old and the new?
7. Should I do anything to stop termites from finding this joint/seam to be a nice place to vacation?



Regarding tying into the office floor (the existing raised slab)
8. Do I need to drill holes and put horizontal rebar here?
9. Do I need to put an expansion joint here?
10. Should I chip out a little of the existing and float the new into that cavity (assuming there is no expansion joint of course)

And lastly, regarding "matching" what the builder did back in 1979...

Here's a closeup of the existing wall to slab area (it's the southeast corner of the office)
What's that metal for? Do I need that? The part that I'm extending is about 3' 6" long so maybe i can get away without it. Maybe length has nothing to do with it. Is it for structure? for drainage? breathing? keeping the wet cement from dripping out while it cures? not sure.



And one last photo to show how thick this slab is (it goes deeper, but I didn't feel like digging all the way to the bottom)