Meeting code on new porch in Atlanta

[Riley Ormsby]

Hello everyone. I'm rebuilding a porch at an investment property in north Atlanta and have 3 questions:

1. What size do the footings of the porch need to be (porch rests on soil, not sand or gravel)?

2. Does the footing have to have rebar?

3. What size do the columns have to be holding up the roof?

If you have any info on where we can find this information, it'd be greatly appreciated! 

Thanks in advance!