i am getting ready to build my concrete porches to replace old wooden porches. i need some input, answers to questions and maybe links that i cannot find. i have not decided whether i am using block or poured walls under the slab. either way, i will make the footers beefy enough to handle either. i know i should put rebar (forget the technical term) vertically under load bearing points and at the corners. my understanding is that 4 pieces are driven in to act as vertical support for the load above and beyond what the footers provide. how deep into the ground below the footers should they extend? how far into the mass of the footers should they go? to the center? i am pretty sure i will use long pieces of rebar placed horizontally and tied onto the vertical pieces to prevent shifting if cracks occur. if my footers are 24 inches wide, how far inside from the edges should they be? how deep should they be...about half way? someone posted a link concerning concrete construction but i cannot find that thread. does anyone have a link with specs and diagrams?