Thank you for the reply. My wife and myself are still talking about a post and pier addition probably a 12 by 16. The question now is it better to sink a 6 by 6 in the ground 36 inches deep with 16 inches of concrete around it, or, is it better to dig a 16 inch hole 36 inches deep and then fill it with concrete and have it 6 more inches above ground level and then put a 6 by 6 on it with an anchor. The soil that I have is clay. Also, I figured that 6 post spaced evenly should be enough to hold the addition up with no problems and lag bolt the ledger board to the house. Any suggestions or objections will be greatly appriciated. Thank-you