I am still in the planning stage but has anyone tried using a cement substitute in lieu of firebricks? I ask because at around $25 for a 6 pack I started looking around. This stuff is rated at 2200 degrees and is said to be useful for casting stone ovens as well.
http://www.amazon.com/gp/product/B000H5T5EA/?tag=smokingmeatforums-20
http://www.amazon.com/gp/product/B000H5T5EA/?tag=smokingmeatforums-20