I am installing a Casa90. It is sitting on a stand that is too small for the insulation that I want to do. I did not feel like laying the block, plus it can be moved later. I have a double layer of the 2" FB board, and extra inch of blanket. I plan on loading a few inches of 10 to 1 perlite/cement on the top. It is on an over sized pad so I plan on studding it out next year and finishing it with a roof similar to what Ev did, his looked nice. The front base is 5" out from the FB board and the hearth floor is 6 inches up from the base. I would like to just get it ready for rough use until next year but in such a way that I can complete it properly. I plan on having a 18" wide/ approx 6' long strip of granite across the face butted up to the hearth floor and installing an arch on top of that. Anyone have a suggestion on how I can get it water tight and ready for rough use. I was thinking of pouring some concrete 5"x5"x stand width, and then mortaring an FB arch to the front face of the oven mouth. Any ideas would be appreciated, and please do not beat me up on the temp job. I just do not have the time to complete it properly.