I finally began construction of my oven over the weekend, completing the block stand with little difficulty. I have a couple of questions as I move on to the next phase, which I intend to frame this week and pour over the weekend. The 2x6 frame is meant to be cut 1/2 inch shorter than the outside dimensions of the stand. Does this imply that only 1/2 inch of the 2x6 actually rests on the stand, leaving a small lip when the forms are removed? Also, the outside dimensions of my stand are 64x72 inches - does anyony have a rough idea of how much vermiculite, cement and concrete I will need to pour the hearth? Thanks in advance for any replies and thanks to all for the vast amount of information I have accessed over the past months.