What are the order of Layers over the firebrick vault

[davidries]

I am building the vault style oven, and the masterly tail info is odd and hard to understand or decipher. He covers the vault with aluminum foil and then a mix of an unknown mortar or cement mix of some sort. He does this to retain more heat in the dome. None of the forno bravo ovens I've seen on this site do that. I'm not sure I need all that heat above the firebrick vault. So what would the layers be if I just did the vault and the vermiculite format. Aluminum foil, refractory mortar, ceramic fiber blanket, vermiculite?