My cement and tiled uncovered porch was built in the early 1970s and I am pretty sure it is being supported by rebar. I want to know if this is sufficient to support my covered porch (with 4 columns). The porch as it sits now is flush against the house with only one crack that has appeared in the cement.
Where are you located?
A short answer is no. Check your local building code.Typically any thing attached to the structure(house) needs footings deep enough to avoid frost heave,and large enough to hold the weight of the new porch cover.