Eventually, I want to extend the full 18 feet, but for now I am planning to just do the 5 feet by 5.5 feet section in blue. This section will be attached to the existing patio and the house. My plan is this:
Dig out the existing ground by 8 inches deep. This will provide for a 4 inch gravel subbase and a 4 inch patio.
Pour the gravel subbase.
Use stakes and 2x4s to make the frame.
Put in the rebar grid.
Glue asphalt-impregnated fiber board to the existing patio and house to create an isolation joint.
Mix and pour cement.
Screed concrete and smooth out top with 2x4s.
My first question is this: Will I need to insert the rebar grid into the existing concrete and the house foundation? In other words, do I need a better connection between existing concrete and the new concrete or will the isolation joints be fine?
Also, is there anything that I am missing in this plan? Or is there anything that I should be aware of when taking on this project?